diff --git a/packages/app/src/api/core-domain/useCases/SaveDeclaration.ts b/packages/app/src/api/core-domain/useCases/SaveDeclaration.ts
index f8fb36e0e..7250a8474 100644
--- a/packages/app/src/api/core-domain/useCases/SaveDeclaration.ts
+++ b/packages/app/src/api/core-domain/useCases/SaveDeclaration.ts
@@ -13,7 +13,7 @@ import { DeclarationSource } from "@common/core-domain/domain/valueObjects/decla
 import { Siren } from "@common/core-domain/domain/valueObjects/Siren";
 import { type CreateDeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
 import { companyMap } from "@common/core-domain/mappers/companyMap";
-import { AppError, type EntityPropsToJson, type UseCase } from "@common/shared-domain";
+import { AppError, type EntityPropsToJson, type UseCase, ValidationError } from "@common/shared-domain";
 import { PositiveInteger, PositiveNumber } from "@common/shared-domain/domain/valueObjects";
 import { keepEntryBy } from "@common/utils/object";
 import { add, isAfter } from "date-fns";
@@ -102,7 +102,10 @@ export class SaveDeclaration implements UseCase<Input, void> {
       remunerations: {
         cseConsultationDate:
           dto.remunerations?.estCalculable === "oui" ? dto.remunerations.dateConsultationCSE : undefined,
-        favorablePopulation: dto["remunerations-resultat"]?.populationFavorable,
+        favorablePopulation:
+          dto["remunerations"]?.estCalculable === "oui"
+            ? dto["remunerations-resultat"]?.populationFavorable ?? "egalite"
+            : undefined,
         mode: remunerationsMode,
         notComputableReason:
           dto.remunerations?.estCalculable === "non" ? dto.remunerations.motifNonCalculabilité : undefined,
@@ -113,21 +116,21 @@ export class SaveDeclaration implements UseCase<Input, void> {
             ? dto["remunerations-csp"]?.catégories.length
               ? dto["remunerations-csp"].catégories.map(({ nom, tranches }) => ({
                   name: nom,
-                  ranges: keepEntryBy(tranches, val => val !== null),
+                  ranges: keepEntryBy(tranches, val => val !== ""),
                 }))
               : []
             : remunerationsMode === "niveau_autre"
             ? dto["remunerations-coefficient-autre"]?.catégories.length
               ? dto["remunerations-coefficient-autre"].catégories.map(({ nom, tranches }) => ({
                   name: nom,
-                  ranges: keepEntryBy(tranches, val => val !== null),
+                  ranges: keepEntryBy(tranches, val => val !== ""),
                 }))
               : []
             : remunerationsMode === "niveau_branche"
             ? dto["remunerations-coefficient-branche"]?.catégories.length
               ? dto["remunerations-coefficient-branche"].catégories.map(({ nom, tranches }) => ({
                   name: nom,
-                  ranges: keepEntryBy(tranches, val => val !== null),
+                  ranges: keepEntryBy(tranches, val => val !== ""),
                 }))
               : []
             : ([] satisfies Categorie[]),
@@ -136,10 +139,15 @@ export class SaveDeclaration implements UseCase<Input, void> {
         salaryRaises: {
           categories:
             dto.augmentations?.estCalculable === "oui"
-              ? dto.augmentations.catégories.map(category => category.écarts)
+              ? [
+                  dto.augmentations.catégories.ouv === "" ? null : dto.augmentations.catégories.ouv,
+                  dto.augmentations.catégories.emp === "" ? null : dto.augmentations.catégories.emp,
+                  dto.augmentations.catégories.tam === "" ? null : dto.augmentations.catégories.tam,
+                  dto.augmentations.catégories.ic === "" ? null : dto.augmentations.catégories.ic,
+                ]
               : [null, null, null, null],
           favorablePopulation:
-            dto.augmentations?.estCalculable === "oui" ? dto.augmentations.populationFavorable : undefined,
+            dto.augmentations?.estCalculable === "oui" ? dto.augmentations.populationFavorable ?? "egalite" : undefined,
           notComputableReason:
             dto.augmentations?.estCalculable == "non" ? dto.augmentations.motifNonCalculabilité : undefined,
           result: dto.augmentations?.estCalculable === "oui" ? dto.augmentations.résultat : undefined,
@@ -148,12 +156,18 @@ export class SaveDeclaration implements UseCase<Input, void> {
         promotions: {
           notComputableReason:
             dto.promotions?.estCalculable === "non" ? dto.promotions.motifNonCalculabilité : undefined,
-          favorablePopulation: dto.promotions?.estCalculable === "oui" ? dto.promotions.populationFavorable : undefined,
+          favorablePopulation:
+            dto.promotions?.estCalculable === "oui" ? dto.promotions.populationFavorable ?? "egalite" : undefined,
           result: dto.promotions?.estCalculable === "oui" ? dto.promotions.résultat : undefined,
           score: dto.promotions?.estCalculable === "oui" ? dto.promotions.note : undefined,
           categories:
             dto.promotions?.estCalculable === "oui"
-              ? dto.promotions.catégories.map(category => category.écarts)
+              ? [
+                  dto.promotions.catégories.ouv === "" ? null : dto.promotions.catégories.ouv,
+                  dto.promotions.catégories.emp === "" ? null : dto.promotions.catégories.emp,
+                  dto.promotions.catégories.tam === "" ? null : dto.promotions.catégories.tam,
+                  dto.promotions.catégories.ic === "" ? null : dto.promotions.catégories.ic,
+                ]
               : [null, null, null, null],
         },
       }),
@@ -165,7 +179,7 @@ export class SaveDeclaration implements UseCase<Input, void> {
               : undefined,
           favorablePopulation:
             dto["augmentations-et-promotions"]?.estCalculable === "oui"
-              ? dto["augmentations-et-promotions"].populationFavorable
+              ? dto["augmentations-et-promotions"].populationFavorable ?? "egalite"
               : undefined,
           employeesCountResult:
             dto["augmentations-et-promotions"]?.estCalculable === "oui"
@@ -199,11 +213,13 @@ export class SaveDeclaration implements UseCase<Input, void> {
         ? undefined
         : {
             result: dto["hautes-remunerations"].résultat,
-            favorablePopulation: dto["hautes-remunerations"].populationFavorable,
+            favorablePopulation: dto["hautes-remunerations"].populationFavorable ?? "egalite",
             score: dto["hautes-remunerations"].note,
           },
     } satisfies EntityPropsToJson<DeclarationProps>;
 
+    console.log("partialDeclaration", JSON.stringify(partialDeclaration, null, 2));
+
     let declaration: Declaration;
 
     try {
@@ -272,8 +288,8 @@ export class SaveDeclaration implements UseCase<Input, void> {
         throw specification.lastError;
       }
     } catch (error: unknown) {
-      if (error instanceof DeclarationSpecificationError) {
-        console.error(error.message);
+      if (error instanceof DeclarationSpecificationError || error instanceof ValidationError) {
+        console.error(error);
         throw error;
       }
 
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/(remunerations)/RemunerationGenericForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/(remunerations)/RemunerationGenericForm.tsx
index 10e309ac7..206976a2e 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/(remunerations)/RemunerationGenericForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/(remunerations)/RemunerationGenericForm.tsx
@@ -1,18 +1,18 @@
 "use client";
 
 import { fr } from "@codegouvfr/react-dsfr";
-import Alert from "@codegouvfr/react-dsfr/Alert";
 import { Button } from "@codegouvfr/react-dsfr/Button";
 import { cx } from "@codegouvfr/react-dsfr/tools/cx";
 import { CSP } from "@common/core-domain/domain/valueObjects/CSP";
 import { AgeRange } from "@common/core-domain/domain/valueObjects/declaration/AgeRange";
-import { type Catégorie, type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
+import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
 import { type Remunerations } from "@common/models/generated";
-import { zodNumberOrNaNOrNull } from "@common/utils/form";
+import { zodNumberOrEmptyString } from "@common/utils/form";
 import { zodFr } from "@common/utils/zod";
 import { PercentageInput } from "@components/RHF/PercentageInput";
 import { ClientOnly } from "@components/utils/ClientOnly";
 import { SkeletonForm } from "@components/utils/skeleton/SkeletonForm";
+import { AlertMessage } from "@design-system/client";
 import { ClientAnimate } from "@design-system/utils/client/ClientAnimate";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useDeclarationFormManager } from "@services/apiClient/useDeclarationFormManager";
@@ -20,8 +20,9 @@ import { useRouter } from "next/navigation";
 import { FormProvider, useFieldArray, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import { NOT_ALL_EMPTY_CATEGORIES } from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
-import { assertOrRedirectCommencerStep, funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
+import { funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 import style from "./RemunerationGenericForm.module.scss";
 
 const formSchema = zodFr.object({
@@ -30,36 +31,43 @@ const formSchema = zodFr.object({
       z.object({
         nom: z.string(),
         tranches: z.object({
-          [AgeRange.Enum.LESS_THAN_30]: zodNumberOrNaNOrNull,
-          [AgeRange.Enum.FROM_30_TO_39]: zodNumberOrNaNOrNull,
-          [AgeRange.Enum.FROM_40_TO_49]: zodNumberOrNaNOrNull,
-          [AgeRange.Enum.FROM_50_TO_MORE]: zodNumberOrNaNOrNull,
+          [AgeRange.Enum.LESS_THAN_30]: zodNumberOrEmptyString,
+          [AgeRange.Enum.FROM_30_TO_39]: zodNumberOrEmptyString,
+          [AgeRange.Enum.FROM_40_TO_49]: zodNumberOrEmptyString,
+          [AgeRange.Enum.FROM_50_TO_MORE]: zodNumberOrEmptyString,
         }),
       }),
     )
-    .superRefine((val, ctx) => {
-      if (notFilled(val)) {
+    .superRefine((catégories, ctx) => {
+      if (notFilled(catégories)) {
         ctx.addIssue({
           code: z.ZodIssueCode.custom,
-          message: "Vous devez renseigner au moins un écart si votre indicateur est calculable",
+          message: NOT_ALL_EMPTY_CATEGORIES,
         });
       }
     }),
 });
 
-// Infer the TS type according to the zod schema.
-type FormType = z.infer<typeof formSchema>;
-
 const notFilled = (catégories: FormType["catégories"]) =>
   catégories.every(
     catégorie =>
-      catégorie.tranches[AgeRange.Enum.LESS_THAN_30] === null &&
-      catégorie.tranches[AgeRange.Enum.FROM_30_TO_39] === null &&
-      catégorie.tranches[AgeRange.Enum.FROM_40_TO_49] === null &&
-      catégorie.tranches[AgeRange.Enum.FROM_50_TO_MORE] === null,
+      catégorie.tranches[AgeRange.Enum.LESS_THAN_30] === "" &&
+      catégorie.tranches[AgeRange.Enum.FROM_30_TO_39] === "" &&
+      catégorie.tranches[AgeRange.Enum.FROM_40_TO_49] === "" &&
+      catégorie.tranches[AgeRange.Enum.FROM_50_TO_MORE] === "",
   );
 
-const defaultTranch = { ":29": null, "30:39": null, "40:49": null, "50:": null };
+// Infer the TS type according to the zod schema.
+type FormType = z.infer<typeof formSchema>;
+
+type NumberOrEmptyString = number | "";
+
+const defaultTranch = {
+  ":29": "" as NumberOrEmptyString,
+  "30:39": "" as NumberOrEmptyString,
+  "40:49": "" as NumberOrEmptyString,
+  "50:": "" as NumberOrEmptyString,
+};
 
 const buildDefaultCategories = (mode: Remunerations["mode"]) =>
   mode === "csp"
@@ -84,18 +92,20 @@ export const RemunerationGenericForm = ({ mode }: { mode: Remunerations["mode"]
   const router = useRouter();
   const { formData, savePageData } = useDeclarationFormManager();
 
-  assertOrRedirectCommencerStep(formData);
+  // assertOrRedirectCommencerStep(formData);
 
   const methods = useForm<FormType>({
     mode: "onChange",
+    shouldUnregister: true,
     resolver: zodResolver(formSchema),
     defaultValues: formData[stepName] || buildDefaultCategories(mode),
   });
   const {
     control,
+    register,
     handleSubmit,
+    getValues,
     formState: { errors, isValid },
-    setError,
   } = methods;
 
   const {
@@ -111,26 +121,16 @@ export const RemunerationGenericForm = ({ mode }: { mode: Remunerations["mode"]
   });
 
   const onSubmit = async (data: FormType) => {
-    if (notFilled(data.catégories)) {
-      return setError("root.catégories", {
-        message:
-          mode === "csp"
-            ? "Vous devez renseigner les écarts de rémunération pour les CSP et tranches d'âge concernés."
-            : "Vous devez renseigner les écarts de rémunération pour les tranches d'âge concernées.",
-      });
-    }
-
     savePageData(stepName, data as DeclarationDTO[typeof stepName]);
 
     router.push(funnelConfig(formData)[stepName].next().url);
   };
 
-  const getCSPTitle = (catégorie: Catégorie) =>
-    mode === "csp" ? new CSP(catégorie.nom as CSP.Enum).getLabel() : undefined;
-
   return (
     <FormProvider {...methods}>
       <form onSubmit={handleSubmit(onSubmit)} noValidate>
+        <AlertMessage title="Erreur" message={errors.catégories?.root?.message} />
+
         <ClientOnly fallback={<SkeletonForm fields={2} />}>
           <div className={fr.cx("fr-mb-8w")}></div>
 
@@ -140,7 +140,9 @@ export const RemunerationGenericForm = ({ mode }: { mode: Remunerations["mode"]
                 <div className={cx(fr.cx("fr-col"), style["category-title"])}>
                   {/* Name of catégorie doesn't matter when mode is coef, so don't bother with inconsistent name between storage & UI */}
                   <span className={fr.cx("fr-text--bold")}>
-                    {getCSPTitle(catégorie) || `Niveau ou coefficient ${index + 1}`}
+                    {mode === "csp"
+                      ? new CSP(catégorie.nom as CSP.Enum).getLabel()
+                      : `Niveau ou coefficient ${index + 1}`}
                   </span>
                   {mode !== "csp" && (
                     <Button
@@ -175,6 +177,10 @@ export const RemunerationGenericForm = ({ mode }: { mode: Remunerations["mode"]
                           AgeRange.Enum.FROM_50_TO_MORE,
                         ].map(key => (
                           <td key={key}>
+                            <input
+                              {...register(`catégories.${index}.nom`, { value: getValues(`catégories.${index}.nom`) })}
+                              type="hidden"
+                            />
                             <PercentageInput<FormType> name={`catégories.${index}.tranches.${key}`} />
                           </td>
                         ))}
@@ -201,11 +207,6 @@ export const RemunerationGenericForm = ({ mode }: { mode: Remunerations["mode"]
           )}
         </ClientOnly>
 
-        <ClientAnimate>
-          {errors.root?.catégories && (
-            <Alert severity="error" title="Informations manquantes" description={errors.root.catégories.message} />
-          )}
-        </ClientAnimate>
         <BackNextButtons stepName={stepName} disabled={!isValid} />
       </form>
     </FormProvider>
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/actions.ts b/packages/app/src/app/(default)/index-egapro/declaration/actions.ts
index c4b19eb0d..761a6fdac 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/actions.ts
+++ b/packages/app/src/app/(default)/index-egapro/declaration/actions.ts
@@ -10,6 +10,7 @@ import { jsxPdfService } from "@api/shared-domain/infra/pdf";
 import { assertServerSession } from "@api/utils/auth";
 import { DeclarationSpecificationError } from "@common/core-domain/domain/specification/DeclarationSpecification";
 import { type CreateDeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
+import { ValidationError } from "@common/shared-domain";
 import { type ServerActionResponse } from "@common/utils/next";
 import assert from "assert";
 
@@ -69,9 +70,7 @@ export async function saveDeclaration(
       ok: true,
     };
   } catch (error: unknown) {
-    console.error(error);
-
-    if (error instanceof DeclarationSpecificationError) {
+    if (error instanceof DeclarationSpecificationError || error instanceof ValidationError) {
       return {
         ok: false,
         error: error.message ?? error.previousError,
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/augmentations-et-promotions/AugmentationsEtPromotionsForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/augmentations-et-promotions/AugmentationsEtPromotionsForm.tsx
index 6bbc77658..2daf9de94 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/augmentations-et-promotions/AugmentationsEtPromotionsForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/augmentations-et-promotions/AugmentationsEtPromotionsForm.tsx
@@ -6,23 +6,25 @@ import { indicatorNoteMax } from "@common/core-domain/computers/DeclarationCompu
 import { IndicateurDeuxTroisComputer } from "@common/core-domain/computers/IndicateurDeuxTroisComputer";
 import { IndicateurUnComputer } from "@common/core-domain/computers/IndicateurUnComputer";
 import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
+import { zodNumberOrEmptyString } from "@common/utils/form";
 import { zodFr } from "@common/utils/zod";
+import { IndicatorNoteInput } from "@components/RHF/IndicatorNoteInput";
 import { MotifNC } from "@components/RHF/MotifNC";
 import { PercentageInput } from "@components/RHF/PercentageInput";
 import { PopulationFavorable } from "@components/RHF/PopulationFavorable";
 import { RadioOuiNon } from "@components/RHF/RadioOuiNon";
 import { ClientOnly } from "@components/utils/ClientOnly";
 import { SkeletonForm } from "@components/utils/skeleton/SkeletonForm";
-import { IndicatorNote } from "@design-system";
 import { ClientAnimate } from "@design-system/utils/client/ClientAnimate";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useDeclarationFormManager } from "@services/apiClient/useDeclarationFormManager";
 import { produce } from "immer";
 import { useRouter } from "next/navigation";
-import { useEffect, useState } from "react";
+import { useEffect } from "react";
 import { FormProvider, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import { MANDATORY_FAVORABLE_POPULATION, MANDATORY_RESULT, NOT_BELOW_0 } from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
 import { assertOrRedirectCommencerStep, funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 
@@ -35,10 +37,8 @@ const formSchema = zodFr
     zodFr.object({
       estCalculable: z.literal("oui"),
       populationFavorable: z.string().optional(),
-      résultat: z
-        .number({ invalid_type_error: "Le résultat est obligatoire" })
-        .nonnegative("Le résultat ne peut pas être inférieur à 0"),
-      résultatEquivalentSalarié: z.number({ invalid_type_error: "Le résultat est obligatoire" }).nonnegative(),
+      résultat: zodNumberOrEmptyString, // Infered as number | string for usage in this React Component (see below).
+      résultatEquivalentSalarié: zodNumberOrEmptyString,
       note: z.number().optional(),
       notePourcentage: z.number().optional(),
       noteNombreSalaries: z.number().optional(),
@@ -46,10 +46,40 @@ const formSchema = zodFr
   ])
   .superRefine((value, ctx) => {
     if (value.estCalculable === "oui") {
+      if (value.résultat === "") {
+        // But it won't accept an empty string thanks to superRefine rule.
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: MANDATORY_RESULT,
+          path: ["résultat"],
+        });
+      } else if (value.résultat < 0) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: NOT_BELOW_0,
+          path: ["résultat"],
+        });
+      }
+
+      if (value.résultatEquivalentSalarié === "") {
+        // But it won't accept an empty string thanks to superRefine rule.
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: MANDATORY_RESULT,
+          path: ["résultatEquivalentSalarié"],
+        });
+      } else if (value.résultatEquivalentSalarié < 0) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: NOT_BELOW_0,
+          path: ["résultatEquivalentSalarié"],
+        });
+      }
+
       if ((value.résultat !== 0 || value.résultatEquivalentSalarié !== 0) && !value.populationFavorable) {
         ctx.addIssue({
           code: z.ZodIssueCode.custom,
-          message: "La population envers laquelle l'écart est favorable est obligatoire",
+          message: MANDATORY_FAVORABLE_POPULATION,
           path: ["populationFavorable"],
         });
       }
@@ -66,8 +96,6 @@ export const AugmentationEtPromotionsForm = () => {
 
   assertOrRedirectCommencerStep(formData);
 
-  const [populationFavorableDisabled, setPopulationFavorableDisabled] = useState<boolean>();
-
   const methods = useForm<FormType>({
     mode: "onChange",
     shouldUnregister: true,
@@ -100,40 +128,22 @@ export const AugmentationEtPromotionsForm = () => {
   // Sync notes and populationFavorable with result fields.
   useEffect(() => {
     let notePourcentage, noteNombreSalaries;
-    if (résultat !== undefined && résultat !== null) {
+    if (résultat !== undefined && résultat !== "") {
       notePourcentage = new IndicateurDeuxTroisComputer(new IndicateurUnComputer()).computeNote(résultat);
-      setValue("notePourcentage", notePourcentage);
+      setValue("notePourcentage", notePourcentage, { shouldValidate: true });
     }
-    if (résultatEquivalentSalarié !== undefined && résultatEquivalentSalarié !== null) {
+    if (résultatEquivalentSalarié !== undefined && résultatEquivalentSalarié !== "") {
       noteNombreSalaries = new IndicateurDeuxTroisComputer(new IndicateurUnComputer()).computeNote(
         résultatEquivalentSalarié,
       );
-      setValue("noteNombreSalaries", noteNombreSalaries);
+      setValue("noteNombreSalaries", noteNombreSalaries, { shouldValidate: true });
     }
     if (notePourcentage !== undefined && noteNombreSalaries !== undefined) {
-      setValue("note", Math.max(notePourcentage, noteNombreSalaries));
+      setValue("note", Math.max(notePourcentage, noteNombreSalaries), { shouldValidate: true });
     }
 
     // If it is a compensation, we set the note to the max value.
-    if (estUnRattrapage) setValue("note", indicatorNoteMax[stepName]);
-
-    if (résultat === 0 && résultatEquivalentSalarié === 0) {
-      setPopulationFavorableDisabled(true);
-      setValue("populationFavorable", "");
-    } else {
-      setPopulationFavorableDisabled(false);
-    }
-
-    // RHF recommends to register before using setValue. Seems to work without it though.
-    if (estCalculable === "non") {
-      unregister("notePourcentage");
-      unregister("noteNombreSalaries");
-      unregister("note");
-    } else if (estCalculable === "oui") {
-      register("notePourcentage");
-      register("noteNombreSalaries");
-      register("note");
-    }
+    if (estUnRattrapage) setValue("note", indicatorNoteMax[stepName], { shouldValidate: true });
   }, [
     estCalculable,
     estUnRattrapage,
@@ -178,19 +188,19 @@ export const AugmentationEtPromotionsForm = () => {
                   min={0}
                 />
 
-                <PopulationFavorable disabled={populationFavorableDisabled} />
+                {(résultat !== 0 || résultatEquivalentSalarié !== 0) && <PopulationFavorable />}
 
                 {notePourcentage !== undefined && (
-                  <IndicatorNote
-                    note={notePourcentage}
+                  <IndicatorNoteInput
+                    name="notePourcentage"
                     max={indicatorNoteMax[stepName]}
                     text="Nombre de points obtenus sur le résultat final en %"
                   />
                 )}
 
                 {noteNombreSalaries !== undefined && (
-                  <IndicatorNote
-                    note={noteNombreSalaries}
+                  <IndicatorNoteInput
+                    name="noteNombreSalaries"
                     max={indicatorNoteMax[stepName]}
                     text="Nombre de points obtenus sur le résultat final en nombre équivalent de salariés"
                     className={fr.cx("fr-mt-2w")}
@@ -199,8 +209,7 @@ export const AugmentationEtPromotionsForm = () => {
 
                 {note !== undefined && (
                   <>
-                    <IndicatorNote
-                      note={note}
+                    <IndicatorNoteInput
                       max={indicatorNoteMax[stepName]}
                       text="Nombre de points obtenus à l'indicateur"
                       className={fr.cx("fr-mt-2w")}
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/augmentations/AugmentationsForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/augmentations/AugmentationsForm.tsx
index 999823c96..b31cbacc8 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/augmentations/AugmentationsForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/augmentations/AugmentationsForm.tsx
@@ -7,37 +7,35 @@ import { IndicateurDeuxComputer } from "@common/core-domain/computers/Indicateur
 import { IndicateurUnComputer } from "@common/core-domain/computers/IndicateurUnComputer";
 import { CSP } from "@common/core-domain/domain/valueObjects/CSP";
 import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
-import { zodNumberOrNaNOrNull } from "@common/utils/form";
+import { zodNumberOrEmptyString } from "@common/utils/form";
 import { zodFr } from "@common/utils/zod";
+import { IndicatorNoteInput } from "@components/RHF/IndicatorNoteInput";
 import { MotifNC } from "@components/RHF/MotifNC";
 import { PercentageInput } from "@components/RHF/PercentageInput";
 import { PopulationFavorable } from "@components/RHF/PopulationFavorable";
 import { RadioOuiNon } from "@components/RHF/RadioOuiNon";
 import { ClientOnly } from "@components/utils/ClientOnly";
 import { SkeletonForm } from "@components/utils/skeleton/SkeletonForm";
-import { IndicatorNote } from "@design-system";
 import { ClientAnimate } from "@design-system/utils/client/ClientAnimate";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useDeclarationFormManager } from "@services/apiClient/useDeclarationFormManager";
 import { produce } from "immer";
 import { useRouter } from "next/navigation";
-import { useEffect, useState } from "react";
+import { useEffect } from "react";
 import { FormProvider, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import {
+  MANDATORY_FAVORABLE_POPULATION,
+  MANDATORY_RESULT,
+  NOT_ALL_EMPTY_CATEGORIES,
+  NOT_BELOW_0,
+} from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
-// Import your language translation files
 import { assertOrRedirectCommencerStep, funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 
 const stepName: FunnelKey = "augmentations";
 
-const zodCategories = z.tuple([
-  z.object({ nom: z.literal(CSP.Enum.OUVRIERS), écarts: zodNumberOrNaNOrNull }),
-  z.object({ nom: z.literal(CSP.Enum.EMPLOYES), écarts: zodNumberOrNaNOrNull }),
-  z.object({ nom: z.literal(CSP.Enum.TECHNICIENS_AGENTS_MAITRISES), écarts: zodNumberOrNaNOrNull }),
-  z.object({ nom: z.literal(CSP.Enum.INGENIEURS_CADRES), écarts: zodNumberOrNaNOrNull }),
-]);
-
 const formSchema = zodFr
   .discriminatedUnion("estCalculable", [
     zodFr.object({
@@ -47,27 +45,44 @@ const formSchema = zodFr
     zodFr.object({
       estCalculable: z.literal("oui"),
       populationFavorable: z.string().optional(),
-      résultat: z
-        .number({ invalid_type_error: "Le résultat est obligatoire" })
-        .nonnegative("Le résultat ne peut pas être inférieur à 0"),
+      résultat: zodNumberOrEmptyString, // Infered as number | string for usage in this React Component (see below).
       note: z.number(),
-      catégories: zodCategories,
+      catégories: z.object({
+        [CSP.Enum.OUVRIERS]: zodNumberOrEmptyString,
+        [CSP.Enum.EMPLOYES]: zodNumberOrEmptyString,
+        [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: zodNumberOrEmptyString,
+        [CSP.Enum.INGENIEURS_CADRES]: zodNumberOrEmptyString,
+      }),
     }),
   ])
   .superRefine((value, ctx) => {
     if (value.estCalculable === "oui") {
+      if (value.résultat === "") {
+        // But it won't accept an empty string thanks to superRefine rule.
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: MANDATORY_RESULT,
+          path: ["résultat"],
+        });
+      } else if (value.résultat < 0) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: NOT_BELOW_0,
+          path: ["résultat"],
+        });
+      }
       if (value.résultat !== 0 && !value.populationFavorable) {
         ctx.addIssue({
           code: z.ZodIssueCode.custom,
-          message: "La population envers laquelle l'écart est favorable est obligatoire",
+          message: MANDATORY_FAVORABLE_POPULATION,
           path: ["populationFavorable"],
         });
       }
 
-      if (!value.catégories.some(catégorie => catégorie.écarts !== null)) {
+      if (Object.values(value.catégories).every(val => val === "")) {
         ctx.addIssue({
           code: z.ZodIssueCode.custom,
-          message: "Au moins une catégorie doit avoir un écart renseigné",
+          message: NOT_ALL_EMPTY_CATEGORIES,
           path: ["catégories"],
         });
       }
@@ -76,47 +91,29 @@ const formSchema = zodFr
 
 type FormType = z.infer<typeof formSchema>;
 
-const emptyCSPEcarts = [
-  { nom: CSP.Enum.OUVRIERS, écarts: null },
-  { nom: CSP.Enum.EMPLOYES, écarts: null },
-  { nom: CSP.Enum.TECHNICIENS_AGENTS_MAITRISES, écarts: null },
-  { nom: CSP.Enum.INGENIEURS_CADRES, écarts: null },
-] as const;
-
 export const AugmentationsForm = () => {
   const router = useRouter();
   const { formData, saveFormData } = useDeclarationFormManager();
 
   assertOrRedirectCommencerStep(formData);
 
-  const [populationFavorableDisabled, setPopulationFavorableDisabled] = useState<boolean>();
-
   const methods = useForm<FormType>({
-    // shouldUnregister: true,
+    shouldUnregister: true,
     mode: "onChange",
     resolver: zodResolver(formSchema),
-    defaultValues: formData[stepName] || {
-      catégories: [...emptyCSPEcarts],
-    },
+    defaultValues: formData[stepName],
   });
 
   const {
-    register,
     handleSubmit,
     formState: { isValid, errors: _errors },
     setValue,
     watch,
   } = methods;
 
-  useEffect(() => {
-    register("note");
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, []);
-
   const résultat = watch("résultat");
   const note = watch("note");
   const estCalculable = watch("estCalculable");
-  const catégories = watch("catégories");
   const populationFavorable = watch("populationFavorable");
 
   const estUnRattrapage =
@@ -124,30 +121,15 @@ export const AugmentationsForm = () => {
     populationFavorable &&
     formData["remunerations-resultat"]?.populationFavorable !== populationFavorable;
 
-  useEffect(() => {
-    if (estCalculable === "oui") {
-      if (!catégories?.length) {
-        setValue("catégories", [...emptyCSPEcarts]);
-      }
-    }
-  }, [setValue, catégories, estCalculable]);
-
   useEffect(() => {
     if (résultat !== undefined) {
-      if (résultat !== null) {
+      if (résultat !== "") {
         const note = new IndicateurDeuxComputer(new IndicateurUnComputer()).computeNote(résultat);
         setValue("note", note);
       }
 
       // If it is a compensation, we set the note to the max value.
       if (estUnRattrapage) setValue("note", indicatorNoteMax[stepName]);
-
-      if (résultat === 0 || résultat === null) {
-        setPopulationFavorableDisabled(true);
-        setValue("populationFavorable", "");
-      } else {
-        setPopulationFavorableDisabled(false);
-      }
     }
   }, [estUnRattrapage, résultat, setValue]);
 
@@ -185,21 +167,26 @@ export const AugmentationsForm = () => {
                   à la faveur des hommes et un écart négatif est à la faveur des femmes.
                 </p>
 
-                <PercentageInput<FormType> label="Ouvriers" name="catégories.0.écarts" />
-                <PercentageInput<FormType> label="Employés" name="catégories.1.écarts" />
-                <PercentageInput<FormType> label="Techniciens et agents de maîtrise" name="catégories.2.écarts" />
-                <PercentageInput<FormType> label="Ingénieurs et cadres" name="catégories.3.écarts" />
+                <PercentageInput<FormType> label="Ouvriers" name={`catégories.${CSP.Enum.OUVRIERS}`} />
+                <PercentageInput<FormType> label="Employés" name={`catégories.${CSP.Enum.EMPLOYES}`} />
+                <PercentageInput<FormType>
+                  label="Techniciens et agents de maîtrise"
+                  name={`catégories.${CSP.Enum.TECHNICIENS_AGENTS_MAITRISES}`}
+                />
+                <PercentageInput<FormType>
+                  label="Ingénieurs et cadres"
+                  name={`catégories.${CSP.Enum.INGENIEURS_CADRES}`}
+                />
 
                 <br />
 
                 <PercentageInput<FormType> label="Résultat final obtenu à l'indicateur en %" name="résultat" min={0} />
 
-                <PopulationFavorable disabled={populationFavorableDisabled} />
+                {résultat !== 0 && résultat !== null && <PopulationFavorable />}
 
                 {note !== undefined && (
                   <>
-                    <IndicatorNote
-                      note={note}
+                    <IndicatorNoteInput
                       max={indicatorNoteMax[stepName]}
                       text="Nombre de points obtenus à l'indicateur"
                     />
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/commencer/CommencerForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/commencer/CommencerForm.tsx
index 49325751d..214ec3856 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/commencer/CommencerForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/commencer/CommencerForm.tsx
@@ -24,13 +24,12 @@ import { useSession } from "next-auth/react";
 import { FormProvider, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import { API_ERROR, OWNER_ERROR } from "../../../messages";
 import { getDeclaration } from "../actions";
 import { funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 
 const stepName: FunnelKey = "commencer";
 
-const API_ERROR = "Une erreur serveur est survenue. Veuillez recommencer plus tard";
-
 const baseSchema = zodFr.object({
   annéeIndicateurs: z.number(), // No control needed because this is a select with options we provide.
   siren: sirenSchema,
@@ -38,8 +37,6 @@ const baseSchema = zodFr.object({
 
 type FormType = z.infer<typeof baseSchema>;
 
-const OWNER_ERROR = "Vous n'avez pas les droits sur ce Siren.";
-
 const buildFormSchema = (isStaffMember: boolean, companies: Session["user"]["companies"] = []) =>
   isStaffMember
     ? baseSchema
@@ -179,7 +176,7 @@ export const CommencerForm = () => {
 
       setError("siren", {
         type: "manual",
-        message: error instanceof Error ? error.message : "Une erreur est survenue. Veuillez réessayer.",
+        message: error instanceof Error ? error.message : API_ERROR,
       });
     }
   };
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/conges-maternite/CongesMaterniteForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/conges-maternite/CongesMaterniteForm.tsx
index c477fe8cf..4ac1cac55 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/conges-maternite/CongesMaterniteForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/conges-maternite/CongesMaterniteForm.tsx
@@ -4,13 +4,14 @@ import { fr } from "@codegouvfr/react-dsfr";
 import { indicatorNoteMax } from "@common/core-domain/computers/DeclarationComputer";
 import { IndicateurQuatreComputer } from "@common/core-domain/computers/IndicateurQuatreComputer";
 import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
+import { zodNumberOrEmptyString } from "@common/utils/form";
 import { zodFr } from "@common/utils/zod";
+import { IndicatorNoteInput } from "@components/RHF/IndicatorNoteInput";
 import { MotifNC } from "@components/RHF/MotifNC";
 import { PercentageInput } from "@components/RHF/PercentageInput";
 import { RadioOuiNon } from "@components/RHF/RadioOuiNon";
 import { ClientOnly } from "@components/utils/ClientOnly";
 import { SkeletonForm } from "@components/utils/skeleton/SkeletonForm";
-import { IndicatorNote } from "@design-system";
 import { ClientAnimate } from "@design-system/utils/client/ClientAnimate";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useDeclarationFormManager } from "@services/apiClient/useDeclarationFormManager";
@@ -20,23 +21,46 @@ import { useEffect } from "react";
 import { FormProvider, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import { MANDATORY_RESULT, NOT_BELOW_0, NOT_HIGHER_THAN_N_RESULT } from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
 import { assertOrRedirectCommencerStep, funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 
-const formSchema = zodFr.discriminatedUnion("estCalculable", [
-  zodFr.object({
-    estCalculable: z.literal("non"),
-    motifNonCalculabilité: z.string(),
-  }),
-  zodFr.object({
-    estCalculable: z.literal("oui"),
-    résultat: z
-      .number({ invalid_type_error: "Le résultat est obligatoire" })
-      .nonnegative("Le résultat ne peut pas être inférieur à 0")
-      .lte(100, "Le résultat ne peut pas être supérieur à 100%"),
-    note: z.number().optional(),
-  }),
-]);
+const formSchema = zodFr
+  .discriminatedUnion("estCalculable", [
+    zodFr.object({
+      estCalculable: z.literal("non"),
+      motifNonCalculabilité: z.string(),
+    }),
+    zodFr.object({
+      estCalculable: z.literal("oui"),
+      résultat: zodNumberOrEmptyString, // Infered as number | string for usage in this React Component (see below).
+      note: z.number().optional(),
+    }),
+  ])
+  .superRefine((value, ctx) => {
+    if (value.estCalculable === "oui") {
+      if (value.résultat === "") {
+        // But it won't accept an empty string thanks to superRefine rule.
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: MANDATORY_RESULT,
+          path: ["résultat"],
+        });
+      } else if (value.résultat < 0) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: NOT_BELOW_0,
+          path: ["résultat"],
+        });
+      } else if (value.résultat > 100) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: NOT_HIGHER_THAN_N_RESULT(100) + "%",
+          path: ["résultat"],
+        });
+      }
+    }
+  });
 
 type FormType = z.infer<typeof formSchema>;
 
@@ -50,12 +74,12 @@ export const CongesMaterniteForm = () => {
 
   const methods = useForm<FormType>({
     mode: "onChange",
+    shouldUnregister: true,
     resolver: zodResolver(formSchema),
     defaultValues: formData[stepName],
   });
 
   const {
-    register,
     handleSubmit,
     setValue,
     formState: { isValid, errors: _errors },
@@ -67,12 +91,7 @@ export const CongesMaterniteForm = () => {
   const estCalculable = watch("estCalculable");
 
   useEffect(() => {
-    register("note");
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, []);
-
-  useEffect(() => {
-    if (résultat !== null && résultat !== undefined) {
+    if (résultat !== "" && résultat !== undefined) {
       const resultAsFloat = Math.floor(résultat / 100);
       const note = new IndicateurQuatreComputer().computeNote(resultAsFloat);
       setValue("note", note);
@@ -113,8 +132,7 @@ export const CongesMaterniteForm = () => {
 
                     {note !== undefined && (
                       <>
-                        <IndicatorNote
-                          note={note}
+                        <IndicatorNoteInput
                           max={indicatorNoteMax[stepName]}
                           text="Nombre de points obtenus à l'indicateur"
                           className={fr.cx("fr-mt-2w")}
diff --git "a/packages/app/src/app/(default)/index-egapro/declaration/hautes-remunerations/HautesR\303\251mun\303\251rationsForm.tsx" "b/packages/app/src/app/(default)/index-egapro/declaration/hautes-remunerations/HautesR\303\251mun\303\251rationsForm.tsx"
index b0419f0b4..28e29f7a8 100644
--- "a/packages/app/src/app/(default)/index-egapro/declaration/hautes-remunerations/HautesR\303\251mun\303\251rationsForm.tsx"
+++ "b/packages/app/src/app/(default)/index-egapro/declaration/hautes-remunerations/HautesR\303\251mun\303\251rationsForm.tsx"
@@ -5,37 +5,60 @@ import Input from "@codegouvfr/react-dsfr/Input";
 import { indicatorNoteMax } from "@common/core-domain/computers/DeclarationComputer";
 import { IndicateurCinqComputer } from "@common/core-domain/computers/IndicateurCinqComputer";
 import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
-import { zodPositiveOrZeroIntegerSchema } from "@common/utils/form";
+import { zodNumberOrEmptyString } from "@common/utils/form";
+import { IndicatorNoteInput } from "@components/RHF/IndicatorNoteInput";
 import { PopulationFavorable } from "@components/RHF/PopulationFavorable";
 import { ClientOnly } from "@components/utils/ClientOnly";
 import { SkeletonForm } from "@components/utils/skeleton/SkeletonForm";
-import { IndicatorNote } from "@design-system";
 import { useAutoAnimate } from "@formkit/auto-animate/react";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useDeclarationFormManager } from "@services/apiClient/useDeclarationFormManager";
 import { produce } from "immer";
 import { get } from "lodash";
 import { useRouter } from "next/navigation";
-import { useEffect, useState } from "react";
+import { useEffect } from "react";
 import { FormProvider, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import {
+  MANDATORY_FAVORABLE_POPULATION,
+  MANDATORY_RESULT,
+  NOT_BELOW_0,
+  NOT_HIGHER_THAN_N_RESULT,
+} from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
 import { assertOrRedirectCommencerStep, funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 
 const formSchema = z
   .object({
-    populationFavorable: z.string(),
-    résultat: zodPositiveOrZeroIntegerSchema
-      .min(0, { message: "La valeur minimale est 0" })
-      .max(5, { message: "Le résultat ne peut pas être supérieur à 5" }),
+    populationFavorable: z.string().optional(),
+    résultat: zodNumberOrEmptyString, // Infered as number | string for usage in this React Component (see below).
     note: z.number().optional(),
   })
   .superRefine(({ résultat, populationFavorable }, ctx) => {
-    if (résultat !== 5 && !populationFavorable) {
+    if (résultat === "") {
+      // But it won't accept an empty string thanks to superRefine rule.
       ctx.addIssue({
         code: z.ZodIssueCode.custom,
-        message: "La population envers laquelle l'écart est favorable est obligatoire",
+        message: MANDATORY_RESULT,
+        path: ["résultat"],
+      });
+    } else if (résultat < 0) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: NOT_BELOW_0,
+        path: ["résultat"],
+      });
+    } else if (résultat > 5) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: NOT_HIGHER_THAN_N_RESULT(5),
+        path: ["résultat"],
+      });
+    } else if (résultat !== 5 && !populationFavorable) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: MANDATORY_FAVORABLE_POPULATION,
         path: ["populationFavorable"],
       });
     }
@@ -52,11 +75,10 @@ export const HautesRémunérationsForm = () => {
 
   assertOrRedirectCommencerStep(formData);
 
-  const [populationFavorableDisabled, setPopulationFavorableDisabled] = useState<boolean>();
-
   const methods = useForm<FormType>({
-    resolver: zodResolver(formSchema),
     mode: "onChange",
+    shouldUnregister: true,
+    resolver: zodResolver(formSchema),
     defaultValues: formData[stepName],
   });
 
@@ -68,25 +90,14 @@ export const HautesRémunérationsForm = () => {
     watch,
   } = methods;
 
-  useEffect(() => {
-    register("note");
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, []);
-
   const résultat = watch("résultat");
   const note = watch("note");
 
   useEffect(() => {
-    if (résultat !== undefined) {
+    if (résultat !== "") {
       const note = new IndicateurCinqComputer().computeNote(résultat);
       setValue("note", note);
     }
-    if (résultat === 5) {
-      setPopulationFavorableDisabled(true);
-      setValue("populationFavorable", "");
-    } else {
-      setPopulationFavorableDisabled(false);
-    }
   }, [résultat, setValue]);
 
   const onSubmit = async (data: FormType) => {
@@ -113,12 +124,12 @@ export const HautesRémunérationsForm = () => {
                   max: 5,
                   step: 1,
                   ...register("résultat", {
-                    valueAsNumber: true,
-                    // setValueAs: (value: string) => {
-                    //   // We implement our own valueAsNumber because valueAsNumber returns NaN for empty string and we want null instead.
-                    //   const num = Number(value);
-                    //   return isNaN(num) || value === "" ? null : num;
-                    // },
+                    setValueAs: (value: string | null) => {
+                      // We implement our own valueAsNumber because valueAsNumber returns NaN for empty string and we want null instead for consistency.
+                      if (value === null) return null;
+                      const num = Number(value);
+                      return isNaN(num) || value === "" ? null : num;
+                    },
                   }),
                 }}
                 state={get(errors, "résultat") && "error"}
@@ -127,12 +138,11 @@ export const HautesRémunérationsForm = () => {
                 stateRelatedMessage={get(errors, "résultat")?.message || ""}
               />
 
-              <PopulationFavorable legend="Sexe des salariés sur-représentés" disabled={populationFavorableDisabled} />
+              {résultat !== 5 && <PopulationFavorable legend="Sexe des salariés sur-représentés" />}
 
               {note !== undefined && (
                 <>
-                  <IndicatorNote
-                    note={note}
+                  <IndicatorNoteInput
                     max={indicatorNoteMax[stepName]}
                     text="Nombre de points obtenus à l'indicateur"
                     className={fr.cx("fr-mt-2w")}
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/promotions/PromotionsForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/promotions/PromotionsForm.tsx
index 06230e03b..53eab29bd 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/promotions/PromotionsForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/promotions/PromotionsForm.tsx
@@ -5,37 +5,37 @@ import Alert from "@codegouvfr/react-dsfr/Alert";
 import { indicatorNoteMax } from "@common/core-domain/computers/DeclarationComputer";
 import { IndicateurTroisComputer } from "@common/core-domain/computers/IndicateurTroisComputer";
 import { IndicateurUnComputer } from "@common/core-domain/computers/IndicateurUnComputer";
+import { CSP } from "@common/core-domain/domain/valueObjects/CSP";
 import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
-import { zodNumberOrNaNOrNull } from "@common/utils/form";
+import { zodNumberOrEmptyString } from "@common/utils/form";
 import { zodFr } from "@common/utils/zod";
+import { IndicatorNoteInput } from "@components/RHF/IndicatorNoteInput";
 import { MotifNC } from "@components/RHF/MotifNC";
 import { PercentageInput } from "@components/RHF/PercentageInput";
 import { PopulationFavorable } from "@components/RHF/PopulationFavorable";
 import { RadioOuiNon } from "@components/RHF/RadioOuiNon";
 import { ClientOnly } from "@components/utils/ClientOnly";
 import { SkeletonForm } from "@components/utils/skeleton/SkeletonForm";
-import { IndicatorNote } from "@design-system";
 import { ClientAnimate } from "@design-system/utils/client/ClientAnimate";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useDeclarationFormManager } from "@services/apiClient/useDeclarationFormManager";
 import { produce } from "immer";
 import { useRouter } from "next/navigation";
-import { useEffect, useState } from "react";
+import { useEffect } from "react";
 import { FormProvider, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import {
+  MANDATORY_FAVORABLE_POPULATION,
+  MANDATORY_RESULT,
+  NOT_ALL_EMPTY_CATEGORIES,
+  NOT_BELOW_0,
+} from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
 import { assertOrRedirectCommencerStep, funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 
 const stepName: FunnelKey = "promotions";
 
-const zodCategories = z.tuple([
-  z.object({ nom: z.literal("ouv"), écarts: zodNumberOrNaNOrNull }),
-  z.object({ nom: z.literal("emp"), écarts: zodNumberOrNaNOrNull }),
-  z.object({ nom: z.literal("tam"), écarts: zodNumberOrNaNOrNull }),
-  z.object({ nom: z.literal("ic"), écarts: zodNumberOrNaNOrNull }),
-]);
-
 const formSchema = zodFr
   .discriminatedUnion("estCalculable", [
     zodFr.object({
@@ -45,27 +45,44 @@ const formSchema = zodFr
     zodFr.object({
       estCalculable: z.literal("oui"),
       populationFavorable: z.string().optional(),
-      résultat: z
-        .number({ invalid_type_error: "Le résultat est obligatoire" })
-        .nonnegative("Le résultat ne peut pas être inférieur à 0"),
+      résultat: zodNumberOrEmptyString, // Infered as number | string for usage in this React Component (see below).
       note: z.number(),
-      catégories: zodCategories,
+      catégories: z.object({
+        [CSP.Enum.OUVRIERS]: zodNumberOrEmptyString,
+        [CSP.Enum.EMPLOYES]: zodNumberOrEmptyString,
+        [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: zodNumberOrEmptyString,
+        [CSP.Enum.INGENIEURS_CADRES]: zodNumberOrEmptyString,
+      }),
     }),
   ])
   .superRefine((value, ctx) => {
     if (value.estCalculable === "oui") {
+      if (value.résultat === "") {
+        // But it won't accept an empty string thanks to superRefine rule.
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: MANDATORY_RESULT,
+          path: ["résultat"],
+        });
+      } else if (value.résultat < 0) {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: NOT_BELOW_0,
+          path: ["résultat"],
+        });
+      }
       if (value.résultat !== 0 && !value.populationFavorable) {
         ctx.addIssue({
           code: z.ZodIssueCode.custom,
-          message: "La population envers laquelle l'écart est favorable est obligatoire",
+          message: MANDATORY_FAVORABLE_POPULATION,
           path: ["populationFavorable"],
         });
       }
 
-      if (!value.catégories.some(catégorie => catégorie.écarts !== null)) {
+      if (Object.values(value.catégories).every(val => val === "")) {
         ctx.addIssue({
           code: z.ZodIssueCode.custom,
-          message: "Au moins une catégorie doit avoir un écart renseigné",
+          message: NOT_ALL_EMPTY_CATEGORIES,
           path: ["catégories"],
         });
       }
@@ -80,39 +97,23 @@ export const PromotionsForm = () => {
 
   assertOrRedirectCommencerStep(formData);
 
-  const [populationFavorableDisabled, setPopulationFavorableDisabled] = useState<boolean>();
-
   const methods = useForm<FormType>({
-    // shouldUnregister: true,
     mode: "onChange",
+    shouldUnregister: true,
     resolver: zodResolver(formSchema),
-    defaultValues: formData[stepName] || {
-      catégories: [
-        { nom: "ouv", écarts: null },
-        { nom: "emp", écarts: null },
-        { nom: "tam", écarts: null },
-        { nom: "ic", écarts: null },
-      ],
-    },
+    defaultValues: formData[stepName],
   });
 
   const {
-    register,
     handleSubmit,
     formState: { isValid, errors: _errors },
     setValue,
     watch,
   } = methods;
 
-  useEffect(() => {
-    register("note");
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, []);
-
   const résultat = watch("résultat");
   const note = watch("note");
   const estCalculable = watch("estCalculable");
-  const catégories = watch("catégories");
   const populationFavorable = watch("populationFavorable");
 
   const estUnRattrapage =
@@ -120,35 +121,15 @@ export const PromotionsForm = () => {
     populationFavorable &&
     formData["remunerations-resultat"]?.populationFavorable !== populationFavorable;
 
-  useEffect(() => {
-    if (estCalculable === "oui") {
-      if (!catégories?.length) {
-        setValue("catégories", [
-          { nom: "ouv", écarts: null },
-          { nom: "emp", écarts: null },
-          { nom: "tam", écarts: null },
-          { nom: "ic", écarts: null },
-        ]);
-      }
-    }
-  }, [setValue, catégories, estCalculable]);
-
   useEffect(() => {
     if (résultat !== undefined) {
-      if (résultat !== null) {
+      if (résultat !== "") {
         const note = new IndicateurTroisComputer(new IndicateurUnComputer()).computeNote(résultat);
-        setValue("note", note);
+        setValue("note", note, { shouldValidate: true });
       }
 
       // If it is a compensation, we set the note to the max value.
-      if (estUnRattrapage) setValue("note", indicatorNoteMax[stepName]);
-
-      if (résultat === 0 || résultat === null) {
-        setPopulationFavorableDisabled(true);
-        setValue("populationFavorable", "");
-      } else {
-        setPopulationFavorableDisabled(false);
-      }
+      if (estUnRattrapage) setValue("note", indicatorNoteMax[stepName], { shouldValidate: true });
     }
   }, [estUnRattrapage, résultat, setValue]);
 
@@ -190,21 +171,26 @@ export const PromotionsForm = () => {
                   à la faveur des hommes et un écart négatif est à la faveur des femmes.
                 </p>
 
-                <PercentageInput<FormType> label="Ouvriers" name="catégories.0.écarts" />
-                <PercentageInput<FormType> label="Employés" name="catégories.1.écarts" />
-                <PercentageInput<FormType> label="Techniciens et agents de maîtrise" name="catégories.2.écarts" />
-                <PercentageInput<FormType> label="Ingénieurs et cadres" name="catégories.3.écarts" />
+                <PercentageInput<FormType> label="Ouvriers" name={`catégories.${CSP.Enum.OUVRIERS}`} />
+                <PercentageInput<FormType> label="Employés" name={`catégories.${CSP.Enum.EMPLOYES}`} />
+                <PercentageInput<FormType>
+                  label="Techniciens et agents de maîtrise"
+                  name={`catégories.${CSP.Enum.TECHNICIENS_AGENTS_MAITRISES}`}
+                />
+                <PercentageInput<FormType>
+                  label="Ingénieurs et cadres"
+                  name={`catégories.${CSP.Enum.INGENIEURS_CADRES}`}
+                />
 
                 <br />
 
                 <PercentageInput<FormType> label="Résultat final obtenu à l'indicateur en %" name="résultat" min={0} />
 
-                <PopulationFavorable disabled={populationFavorableDisabled} />
+                {résultat !== 0 && résultat !== null && <PopulationFavorable />}
 
                 {note !== undefined && (
                   <>
-                    <IndicatorNote
-                      note={note}
+                    <IndicatorNoteInput
                       max={indicatorNoteMax[stepName]}
                       text="Nombre de points obtenus à l'indicateur"
                     />
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/remunerations-resultat/RemunerationResultatForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/remunerations-resultat/RemunerationResultatForm.tsx
index 4873e3291..898d00892 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/remunerations-resultat/RemunerationResultatForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/remunerations-resultat/RemunerationResultatForm.tsx
@@ -3,20 +3,22 @@
 import { indicatorNoteMax } from "@common/core-domain/computers/DeclarationComputer";
 import { IndicateurUnComputer } from "@common/core-domain/computers/IndicateurUnComputer";
 import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
+import { zodNumberOrEmptyString } from "@common/utils/form";
 import { zodFr } from "@common/utils/zod";
+import { IndicatorNoteInput } from "@components/RHF/IndicatorNoteInput";
 import { PercentageInput } from "@components/RHF/PercentageInput";
 import { PopulationFavorable } from "@components/RHF/PopulationFavorable";
 import { ClientOnly } from "@components/utils/ClientOnly";
 import { SkeletonForm } from "@components/utils/skeleton/SkeletonForm";
-import { IndicatorNote } from "@design-system";
 import { zodResolver } from "@hookform/resolvers/zod";
 import { useDeclarationFormManager } from "@services/apiClient/useDeclarationFormManager";
 import { produce } from "immer";
 import { useRouter } from "next/navigation";
-import { useEffect, useState } from "react";
+import { useEffect } from "react";
 import { FormProvider, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import { MANDATORY_FAVORABLE_POPULATION, MANDATORY_RESULT, NOT_BELOW_0 } from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
 import { assertOrRedirectCommencerStep, funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 
@@ -25,16 +27,27 @@ const stepName: FunnelKey = "remunerations-resultat";
 const formSchema = zodFr
   .object({
     note: z.number(),
-    populationFavorable: z.string(),
-    résultat: z
-      .number({ invalid_type_error: "Le résultat est obligatoire" })
-      .nonnegative("Le résultat ne peut pas être inférieur à 0"),
+    populationFavorable: z.string().optional(),
+    résultat: zodNumberOrEmptyString, // Infered as number | string for usage in this React Component (see below).
   })
   .superRefine(({ résultat, populationFavorable }, ctx) => {
-    if (résultat !== 0 && !populationFavorable) {
+    if (résultat === "") {
+      // But it won't accept an empty string thanks to superRefine rule.
       ctx.addIssue({
         code: z.ZodIssueCode.custom,
-        message: "La population envers laquelle l'écart est favorable est obligatoire",
+        message: MANDATORY_RESULT,
+        path: ["résultat"],
+      });
+    } else if (résultat < 0) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: NOT_BELOW_0,
+        path: ["résultat"],
+      });
+    } else if (résultat !== 0 && !populationFavorable) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: MANDATORY_FAVORABLE_POPULATION,
         path: ["populationFavorable"],
       });
     }
@@ -48,42 +61,27 @@ export const RemunerationResultatForm = () => {
 
   assertOrRedirectCommencerStep(formData);
 
-  const [populationFavorableDisabled, setPopulationFavorableDisabled] = useState<boolean>();
-
   const methods = useForm<FormType>({
     mode: "onChange",
+    shouldUnregister: true,
     resolver: zodResolver(formSchema),
     defaultValues: formData[stepName],
   });
 
   const {
-    register,
     handleSubmit,
     formState: { isValid },
     setValue,
     watch,
   } = methods;
 
-  useEffect(() => {
-    register("note");
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, []);
-
   const résultat = watch("résultat");
-  const note = watch("note");
 
   useEffect(() => {
-    if (résultat !== null) {
+    if (résultat !== "") {
       const note = new IndicateurUnComputer().computeNote(résultat);
       setValue("note", note);
     }
-
-    if (résultat === 0 || résultat === null) {
-      setPopulationFavorableDisabled(true);
-      setValue("populationFavorable", "", { shouldValidate: true });
-    } else {
-      setPopulationFavorableDisabled(false);
-    }
   }, [résultat, setValue]);
 
   const onSubmit = async (data: FormType) => {
@@ -102,15 +100,11 @@ export const RemunerationResultatForm = () => {
         <ClientOnly fallback={<SkeletonForm fields={2} />}>
           <PercentageInput<FormType> label="Résultat final obtenu à l'indicateur en %" name="résultat" min={0} />
 
-          <PopulationFavorable disabled={populationFavorableDisabled} />
+          {résultat !== 0 && résultat !== null && <PopulationFavorable />}
 
-          {résultat !== null && (
+          {résultat !== "" && (
             <>
-              <IndicatorNote
-                note={note}
-                max={indicatorNoteMax.remunerations}
-                text="Nombre de points obtenus à l'indicateur"
-              />
+              <IndicatorNoteInput max={indicatorNoteMax.remunerations} text="Nombre de points obtenus à l'indicateur" />
             </>
           )}
         </ClientOnly>
diff --git a/packages/app/src/app/(default)/index-egapro/declaration/ues/UESForm.tsx b/packages/app/src/app/(default)/index-egapro/declaration/ues/UESForm.tsx
index 6c75ad5ee..e5bec3e46 100644
--- a/packages/app/src/app/(default)/index-egapro/declaration/ues/UESForm.tsx
+++ b/packages/app/src/app/(default)/index-egapro/declaration/ues/UESForm.tsx
@@ -19,15 +19,13 @@ import { useCallback, useEffect, useState } from "react";
 import { FormProvider, useFieldArray, useForm } from "react-hook-form";
 import { z } from "zod";
 
+import { INVALID_SIREN, MANDATORY_SIREN } from "../../../messages";
 import { BackNextButtons } from "../BackNextButtons";
 import { funnelConfig, type FunnelKey } from "../declarationFunnelConfiguration";
 import style from "./UESForm.module.scss";
 
 type ValidateResult = { data?: string; ok: true } | { error: string; ok: false };
 
-const MANDATORY_SIREN_ERROR = "Le Siren est requis";
-const INVALID_SIREN_ERROR = "Le Siren est composé de 9 chiffres sans espace";
-
 const formSchema = zodFr.object({
   nom: z.string().trim().nonempty(),
   entreprises: z
@@ -114,14 +112,14 @@ export const UESForm = () => {
       if (!entrepriseField.siren) {
         setError(`entreprises.${entrepriseFieldIndex}.siren`, {
           type: "custom",
-          message: MANDATORY_SIREN_ERROR,
+          message: MANDATORY_SIREN,
         });
       }
 
       if (!sirenSchema.safeParse(entrepriseField.siren).success) {
         setError(`entreprises.${entrepriseFieldIndex}.siren`, {
           type: "custom",
-          message: INVALID_SIREN_ERROR,
+          message: INVALID_SIREN,
         });
       }
     });
@@ -138,11 +136,11 @@ export const UESForm = () => {
     const parsedSiren = sirenSchema.safeParse(childSiren);
 
     if (!parsedSiren) {
-      return { ok: false, error: MANDATORY_SIREN_ERROR };
+      return { ok: false, error: MANDATORY_SIREN };
     }
 
     if (!parsedSiren.success) {
-      return { ok: false, error: INVALID_SIREN_ERROR };
+      return { ok: false, error: INVALID_SIREN };
     }
 
     // We fetch the latest data for the entreprise to fill the entreprise page.
@@ -269,7 +267,7 @@ export const UESForm = () => {
                                 if (!e.target.value) {
                                   setError(`entreprises.${index}.siren`, {
                                     type: "custom",
-                                    message: MANDATORY_SIREN_ERROR,
+                                    message: MANDATORY_SIREN,
                                   });
                                 }
                               },
diff --git a/packages/app/src/app/(default)/index-egapro/simulateur/(funnel)/recapitulatif/simuToDecla.ts b/packages/app/src/app/(default)/index-egapro/simulateur/(funnel)/recapitulatif/simuToDecla.ts
index 561dd62fc..232ebbdaf 100644
--- a/packages/app/src/app/(default)/index-egapro/simulateur/(funnel)/recapitulatif/simuToDecla.ts
+++ b/packages/app/src/app/(default)/index-egapro/simulateur/(funnel)/recapitulatif/simuToDecla.ts
@@ -1,6 +1,6 @@
 import { type ComputedResult, resultWithSign } from "@common/core-domain/computers/AbstractComputer";
 import { type IndicateurUnComputer } from "@common/core-domain/computers/IndicateurUnComputer";
-import { type CSP } from "@common/core-domain/domain/valueObjects/CSP";
+import { CSP } from "@common/core-domain/domain/valueObjects/CSP";
 import { AgeRange } from "@common/core-domain/domain/valueObjects/declaration/AgeRange";
 import { FavorablePopulation } from "@common/core-domain/domain/valueObjects/declaration/indicators/FavorablePopulation";
 import { RemunerationsMode } from "@common/core-domain/domain/valueObjects/declaration/indicators/RemunerationsMode";
@@ -9,13 +9,13 @@ import {
   isCreateSimulationWorkforceRangeLessThan250DTO,
 } from "@common/core-domain/dtos/CreateSimulationDTO";
 import { type DeclarationDTO } from "@common/core-domain/dtos/DeclarationDTO";
-import { Object } from "@common/utils/overload";
 
 import { computerHelper } from "./computerHelper";
 
+// TODO: use toBinaryFavorablePopulation instead when refactor is made on ComputedResult.favorablePopulation.
 const toFavorablePopulation = (populationFavorable: ComputedResult["favorablePopulation"]) =>
   populationFavorable === "equality"
-    ? FavorablePopulation.Enum.EQUALITY
+    ? undefined
     : populationFavorable === "men"
     ? FavorablePopulation.Enum.MEN
     : FavorablePopulation.Enum.WOMEN;
@@ -23,6 +23,10 @@ const toFavorablePopulation = (populationFavorable: ComputedResult["favorablePop
 const computeGroupIndicateurUn = (computerIndicateurUn: IndicateurUnComputer) => (key: string) =>
   !computerIndicateurUn.canComputeGroup(key) ? null : resultWithSign(computerIndicateurUn.computeGroup(key));
 
+/**
+ * Transform a simulation object store to a declaration object store.
+ *
+ */
 export const simuFunnelToDeclarationDTO = (simulation: CreateSimulationDTO): DeclarationDTO => {
   const {
     computerIndicateurUn,
@@ -84,34 +88,39 @@ export const simuFunnelToDeclarationDTO = (simulation: CreateSimulationDTO): Dec
   } else {
     const indicateur2 = simulation.indicateur2;
 
-    type CatégoriesAugmentations = Extract<DeclarationDTO["augmentations"], { estCalculable: "oui" }>["catégories"];
     // We only care of filling the indicator if it is computable.
     if (indicateur2.calculable && resultIndicateurDeux) {
       dto["augmentations"] = {
         estCalculable: "oui",
-        catégories: Object.keys(indicateur2.pourcentages).map(csp => ({
-          nom: csp,
-          écarts: resultWithSign(computerIndicateurDeux.computeGroup(csp as CSP.Enum)),
-        })) as CatégoriesAugmentations,
+        catégories: {
+          [CSP.Enum.OUVRIERS]: resultWithSign(computerIndicateurDeux.computeGroup(CSP.Enum.OUVRIERS)),
+          [CSP.Enum.EMPLOYES]: resultWithSign(computerIndicateurDeux.computeGroup(CSP.Enum.EMPLOYES)),
+          [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: resultWithSign(
+            computerIndicateurDeux.computeGroup(CSP.Enum.TECHNICIENS_AGENTS_MAITRISES),
+          ),
+          [CSP.Enum.INGENIEURS_CADRES]: resultWithSign(computerIndicateurDeux.computeGroup(CSP.Enum.INGENIEURS_CADRES)),
+        },
         note: resultIndicateurDeux.note,
-        populationFavorable: toFavorablePopulation(resultIndicateurDeux.favorablePopulation),
+        populationFavorable: toFavorablePopulation(resultIndicateurDeux.favorablePopulation), // TODO: Use the FavorablePopulation.Enum instead.
         résultat: resultIndicateurDeux.result,
       };
     }
 
     const promotions = simulation.indicateur3;
 
-    type CatégoriesPromotions = Extract<
-      NonNullable<DeclarationDTO["promotions"]>,
-      { estCalculable: "oui" }
-    >["catégories"];
     if (promotions.calculable && resultIndicateurTrois) {
       dto["promotions"] = {
         estCalculable: "oui",
-        catégories: Object.keys(promotions.pourcentages).map(csp => ({
-          nom: csp,
-          écarts: resultWithSign(computerIndicateurTrois.computeGroup(csp as CSP.Enum)),
-        })) as CatégoriesPromotions,
+        catégories: {
+          [CSP.Enum.OUVRIERS]: resultWithSign(computerIndicateurTrois.computeGroup(CSP.Enum.OUVRIERS)),
+          [CSP.Enum.EMPLOYES]: resultWithSign(computerIndicateurTrois.computeGroup(CSP.Enum.EMPLOYES)),
+          [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: resultWithSign(
+            computerIndicateurTrois.computeGroup(CSP.Enum.TECHNICIENS_AGENTS_MAITRISES),
+          ),
+          [CSP.Enum.INGENIEURS_CADRES]: resultWithSign(
+            computerIndicateurTrois.computeGroup(CSP.Enum.INGENIEURS_CADRES),
+          ),
+        },
         note: resultIndicateurTrois.note,
         populationFavorable: toFavorablePopulation(resultIndicateurTrois.favorablePopulation),
         résultat: resultIndicateurTrois.result,
@@ -150,10 +159,10 @@ export const simuFunnelToDeclarationDTO = (simulation: CreateSimulationDTO): Dec
       catégories: indicateur1.remunerations.map(({ name: nom, categoryId }) => ({
         nom,
         tranches: {
-          [AgeRange.Enum.LESS_THAN_30]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}::29`),
-          [AgeRange.Enum.FROM_30_TO_39]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}:30:39`) || null,
-          [AgeRange.Enum.FROM_40_TO_49]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}:40:49`) || null,
-          [AgeRange.Enum.FROM_50_TO_MORE]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}:50:`) || null,
+          [AgeRange.Enum.LESS_THAN_30]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}::29`) || "",
+          [AgeRange.Enum.FROM_30_TO_39]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}:30:39`) || "",
+          [AgeRange.Enum.FROM_40_TO_49]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}:40:49`) || "",
+          [AgeRange.Enum.FROM_50_TO_MORE]: computeGroupIndicateurUn(computerIndicateurUn)(`${categoryId}:50:`) || "",
         },
       })),
     };
@@ -164,12 +173,12 @@ export const simuFunnelToDeclarationDTO = (simulation: CreateSimulationDTO): Dec
       catégories: ["ouv", "emp", "tam", "ic"].map(nom => ({
         nom,
         tranches: {
-          [AgeRange.Enum.LESS_THAN_30]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}::29`),
-          [AgeRange.Enum.FROM_30_TO_39]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}:30:39`),
-          [AgeRange.Enum.FROM_40_TO_49]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}:40:49`),
-          [AgeRange.Enum.FROM_50_TO_MORE]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}:50:`),
+          [AgeRange.Enum.LESS_THAN_30]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}::29`) || "",
+          [AgeRange.Enum.FROM_30_TO_39]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}:30:39`) || "",
+          [AgeRange.Enum.FROM_40_TO_49]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}:40:49`) || "",
+          [AgeRange.Enum.FROM_50_TO_MORE]: computeGroupIndicateurUn(computerIndicateurUn)(`${nom}:50:`) || "",
         },
-      })) as NonNullable<DeclarationDTO["remunerations-csp"]>["catégories"],
+      })) as Exclude<DeclarationDTO["remunerations-csp"], undefined>["catégories"],
     };
   }
 
diff --git a/packages/app/src/app/(default)/messages.tsx b/packages/app/src/app/(default)/messages.tsx
new file mode 100644
index 000000000..8186fb631
--- /dev/null
+++ b/packages/app/src/app/(default)/messages.tsx
@@ -0,0 +1,11 @@
+export const API_ERROR = "Une erreur serveur est survenue. Veuillez réessayer.";
+
+export const OWNER_ERROR = "Vous n'avez pas les droits sur ce Siren.";
+export const MANDATORY_RESULT = "Le résultat est obligatoire";
+export const NOT_BELOW_N_RESULT = (n: number) => `Le résultat ne peut pas être inférieur à ${n}`;
+export const NOT_BELOW_0 = NOT_BELOW_N_RESULT(0);
+export const MANDATORY_FAVORABLE_POPULATION = "La population envers laquelle l'écart est favorable est obligatoire";
+export const NOT_HIGHER_THAN_N_RESULT = (n: number) => `Le résultat ne peut pas être supérieur à ${n}`;
+export const NOT_ALL_EMPTY_CATEGORIES = "Au moins une catégorie doit avoir un écart renseigné";
+export const MANDATORY_SIREN = "Le Siren est requis";
+export const INVALID_SIREN = "Le Siren est composé de 9 chiffres sans espace";
diff --git a/packages/app/src/common/core-domain/computers/AbstractComputer.ts b/packages/app/src/common/core-domain/computers/AbstractComputer.ts
index 62cea8eb5..0c785b60c 100644
--- a/packages/app/src/common/core-domain/computers/AbstractComputer.ts
+++ b/packages/app/src/common/core-domain/computers/AbstractComputer.ts
@@ -2,7 +2,7 @@ import { type Any } from "@common/utils/types";
 import { last } from "lodash";
 
 export type ComputedResult<Additional extends object = object> = Additional & {
-  favorablePopulation: "equality" | "men" | "women";
+  favorablePopulation: "equality" | "men" | "women"; // TODO: use the FavorablePopulation.Enum instead.
   note: number;
   result: number;
   resultRaw: number;
diff --git a/packages/app/src/common/core-domain/computers/DeclarationComputer.ts b/packages/app/src/common/core-domain/computers/DeclarationComputer.ts
index 5b39e8811..744e1fb8d 100644
--- a/packages/app/src/common/core-domain/computers/DeclarationComputer.ts
+++ b/packages/app/src/common/core-domain/computers/DeclarationComputer.ts
@@ -5,11 +5,15 @@ import { IndicateurQuatreComputer } from "@common/core-domain/computers/Indicate
 import { IndicateurTroisComputer } from "@common/core-domain/computers/IndicateurTroisComputer";
 import { IndicateurUnComputer } from "@common/core-domain/computers/IndicateurUnComputer";
 import { type Declaration } from "@common/core-domain/domain/Declaration";
-import { type DeclarationDTO, type IndicatorKey } from "@common/core-domain/dtos/DeclarationDTO";
+import {
+  type DeclarationDTO,
+  type FavorablePopulationEnum,
+  type IndicatorKey,
+} from "@common/core-domain/dtos/DeclarationDTO";
 import assert from "assert";
 
 import { CompanyWorkforceRange } from "../domain/valueObjects/declaration/CompanyWorkforceRange";
-import { type FavorablePopulation } from "../domain/valueObjects/declaration/indicators/FavorablePopulation";
+import { FavorablePopulation } from "../domain/valueObjects/declaration/indicators/FavorablePopulation";
 
 const indicateurUn = new IndicateurUnComputer();
 const indicateurDeux = new IndicateurDeuxComputer(indicateurUn);
@@ -31,7 +35,7 @@ type IndicatorBase =
   | {
       isComputable: false;
     }
-  | { favorablePopulation: FavorablePopulation.Enum; isComputable: true; result: number };
+  | { favorablePopulation?: FavorablePopulationEnum; isComputable: true; result: number };
 
 type DeclarationComputerInputBase = {
   highRemunerations: Omit<Extract<IndicatorBase, { isComputable: true }>, "isComputable">;
@@ -70,6 +74,16 @@ type DeclarationComputerOutput = {
   points: number;
 };
 
+/** Helper to convert a 3 values favorable population in a 2 values with undefined */
+export const toBinaryFavorablePopulation = (populationFavorable: FavorablePopulation.Enum) =>
+  (populationFavorable === FavorablePopulation.Enum.EQUALITY
+    ? undefined
+    : populationFavorable) as FavorablePopulationEnum;
+
+/** Helper to convert a 2 values favorable population with undefined in a 3 values */
+export const toTernaryFavorablePopulation = (populationFavorable?: FavorablePopulationEnum) =>
+  (!populationFavorable ? FavorablePopulation.Enum.EQUALITY : populationFavorable) as FavorablePopulation.Enum;
+
 export const DeclarationComputerInputBuilder = {
   fromDeclaration(domain: Declaration) {
     // When périodeSuffisante is not "oui", we can't compute the index.
@@ -122,7 +136,7 @@ export const DeclarationComputerInputBuilder = {
       remunerations:
         domain.remunerations.notComputableReason === undefined
           ? {
-              favorablePopulation: domain.remunerations.favorablePopulation!.getValue(),
+              favorablePopulation: toBinaryFavorablePopulation(domain.remunerations.favorablePopulation!.getValue()),
               isComputable: true,
               result: domain.remunerations.result!.getValue() || 0,
             }
@@ -140,17 +154,19 @@ export const DeclarationComputerInputBuilder = {
               isComputable: false,
             },
       highRemunerations: {
-        favorablePopulation: domain.highRemunerations.favorablePopulation.getValue(),
+        favorablePopulation: toBinaryFavorablePopulation(domain.highRemunerations.favorablePopulation.getValue()),
         result: domain.highRemunerations.result.getValue(),
       },
       ...(domain.company.range.getValue() === CompanyWorkforceRange.Enum.FROM_50_TO_250
         ? {
             range: CompanyWorkforceRange.Enum.FROM_50_TO_250,
             salaryRaisesAndPromotions:
-              domain.salaryRaisesAndPromotions!.notComputableReason === undefined // Unfortunatelay, previous assert is ignored by TS.
+              domain.salaryRaisesAndPromotions!.notComputableReason === undefined // Unfortunately, previous assert is ignored by TS.
                 ? {
                     isComputable: true,
-                    favorablePopulation: domain.salaryRaisesAndPromotions!.favorablePopulation!.getValue(),
+                    favorablePopulation: toBinaryFavorablePopulation(
+                      domain.salaryRaisesAndPromotions!.favorablePopulation!.getValue(),
+                    ),
                     result: domain.salaryRaisesAndPromotions!.result!.getValue(),
                     employeesCountResult: domain.salaryRaisesAndPromotions!.employeesCountResult!.getValue(),
                   }
@@ -166,7 +182,9 @@ export const DeclarationComputerInputBuilder = {
               domain.salaryRaises!.notComputableReason === undefined
                 ? {
                     isComputable: true,
-                    favorablePopulation: domain.salaryRaises!.favorablePopulation!.getValue(),
+                    favorablePopulation: toBinaryFavorablePopulation(
+                      domain.salaryRaises!.favorablePopulation!.getValue(),
+                    ),
                     result: domain.salaryRaises!.result!.getValue(),
                   }
                 : {
@@ -176,7 +194,9 @@ export const DeclarationComputerInputBuilder = {
               domain.promotions!.notComputableReason === undefined
                 ? {
                     isComputable: true,
-                    favorablePopulation: domain.promotions!.favorablePopulation!.getValue(),
+                    favorablePopulation: toBinaryFavorablePopulation(
+                      domain.promotions!.favorablePopulation!.getValue(),
+                    ),
                     result: domain.promotions!.result!.getValue(),
                   }
                 : {
@@ -198,10 +218,6 @@ export const DeclarationComputerInputBuilder = {
 
     if (dto.remunerations.estCalculable === "oui") {
       assert(dto["remunerations-resultat"]?.résultat !== undefined, "résultat must be set if indicator is computable");
-      assert(
-        dto["remunerations-resultat"]?.populationFavorable,
-        "populationFavorable must be set if indicator is computable]",
-      );
     }
 
     if (dto.entreprise.tranche === CompanyWorkforceRange.Enum.FROM_50_TO_250) {
@@ -219,10 +235,6 @@ export const DeclarationComputerInputBuilder = {
           dto["augmentations-et-promotions"].résultatEquivalentSalarié !== undefined,
           "résultatEquivalentSalarié must be set if indicator is computable",
         );
-        assert(
-          dto["augmentations-et-promotions"].populationFavorable,
-          "populationFavorable must be set if indicator is computable]",
-        );
       }
     } else {
       assert(dto.augmentations?.estCalculable !== undefined, "augmentations.estCalculable must be set");
@@ -230,11 +242,9 @@ export const DeclarationComputerInputBuilder = {
 
       if (dto.augmentations.estCalculable === "oui") {
         assert(dto.augmentations.résultat !== undefined, "résultat must be set if indicator is computable");
-        assert(dto.augmentations.populationFavorable, "populationFavorable must be set if indicator is computable");
       }
       if (dto.promotions.estCalculable === "oui") {
         assert(dto.promotions.résultat !== undefined, "résultat must be set if indicator is computable");
-        assert(dto.promotions.populationFavorable, "populationFavorable must be set if indicator is computable");
       }
     }
 
diff --git a/packages/app/src/common/core-domain/domain/specification/DeclarationSpecification.ts b/packages/app/src/common/core-domain/domain/specification/DeclarationSpecification.ts
index 6ea14fd4f..c0f46cc29 100644
--- a/packages/app/src/common/core-domain/domain/specification/DeclarationSpecification.ts
+++ b/packages/app/src/common/core-domain/domain/specification/DeclarationSpecification.ts
@@ -4,6 +4,7 @@ import assert, { AssertionError } from "assert";
 
 import { type Declaration } from "../Declaration";
 import { CompanyWorkforceRange } from "../valueObjects/declaration/CompanyWorkforceRange";
+import { FavorablePopulation } from "../valueObjects/declaration/indicators/FavorablePopulation";
 import { type NotComputableReason } from "../valueObjects/declaration/indicators/NotComputableReason";
 import { RemunerationsMode } from "../valueObjects/declaration/indicators/RemunerationsMode";
 
@@ -187,7 +188,7 @@ export class DeclarationSpecification extends AbstractSpecification<Declaration>
           }
         }
 
-        type IndicatorRule9 = { favorablePopulation?: string; result?: Percentage } | undefined;
+        type IndicatorRule9 = { favorablePopulation?: FavorablePopulation; result?: Percentage } | undefined;
 
         const indicatorsRule9 = [
           [declaration.remunerations, "rémunérations"],
@@ -199,8 +200,8 @@ export class DeclarationSpecification extends AbstractSpecification<Declaration>
         for (const [indicator, name] of indicatorsRule9) {
           if (indicator?.result?.getValue() === 0) {
             assert(
-              indicator?.favorablePopulation === undefined,
-              `La population favorable doit être absente pour l'indicateur ${name} quand le résultat est 0.`,
+              indicator?.favorablePopulation?.getValue() === FavorablePopulation.Enum.EQUALITY,
+              `La population favorable doit être à égalité pour l'indicateur ${name} quand le résultat est 0.`,
             );
           }
         }
@@ -211,16 +212,17 @@ export class DeclarationSpecification extends AbstractSpecification<Declaration>
           declaration.salaryRaisesAndPromotions?.employeesCountResult?.getValue() === 0
         ) {
           assert(
-            declaration.salaryRaisesAndPromotions?.favorablePopulation === undefined,
-            "La population favorable doit être absente pour l'indicateur augmentations et promotions quand le résultat est 0 et que le résultat en nombre de salariés est aussi 0.",
+            declaration.salaryRaisesAndPromotions?.favorablePopulation?.getValue() ===
+              FavorablePopulation.Enum.EQUALITY,
+            "La population favorable doit être à égalité pour l'indicateur augmentations et promotions quand le résultat est 0 et que le résultat en nombre de salariés est aussi 0.",
           );
         }
 
         // Règle 11 - Population favorable pour l'indicateur hautes rémunérations
         if (declaration.highRemunerations?.result?.getValue() === 5) {
           assert(
-            declaration.highRemunerations?.favorablePopulation === undefined,
-            "La population favorable doit être absente pour l'indicateur hautes rémunérations quand le résultat est 5.",
+            declaration.highRemunerations?.favorablePopulation.getValue() === FavorablePopulation.Enum.EQUALITY,
+            "La population favorable doit être à égalité pour l'indicateur hautes rémunérations quand le résultat est 5.",
           );
         }
 
diff --git a/packages/app/src/common/core-domain/dtos/DeclarationDTO.ts b/packages/app/src/common/core-domain/dtos/DeclarationDTO.ts
index 742ead00b..62a7e1091 100644
--- a/packages/app/src/common/core-domain/dtos/DeclarationDTO.ts
+++ b/packages/app/src/common/core-domain/dtos/DeclarationDTO.ts
@@ -14,7 +14,7 @@ import { NotComputableReason } from "../domain/valueObjects/declaration/indicato
 
 type OuiNon = "non" | "oui";
 
-type TranchesAge = Record<AgeRange.Enum, number | null>;
+type TranchesAge = Record<AgeRange.Enum, number | "">;
 
 export type Catégorie = { nom: string; tranches: TranchesAge };
 
@@ -42,6 +42,8 @@ export type Entreprise = {
 
 export type IndicatorKeyWithNC = Exclude<IndicatorKey, "hautes-remunerations">;
 
+export type FavorablePopulationEnum = FavorablePopulation.Enum.MEN | FavorablePopulation.Enum.WOMEN;
+
 export const motifsNC = {
   augmentations: [NotComputableReason.Enum.EGVI40PCET, NotComputableReason.Enum.ABSAUGI],
   promotions: [NotComputableReason.Enum.EGVI40PCET, NotComputableReason.Enum.ABSPROM],
@@ -68,15 +70,15 @@ export const remunerationsStateFromMode = (mode: Remunerations["mode"]): remuner
 export type DeclarationDTO = {
   augmentations?:
     | {
-        catégories: [
-          { nom: CSP.Enum.OUVRIERS; écarts: number | null },
-          { nom: CSP.Enum.EMPLOYES; écarts: number | null },
-          { nom: CSP.Enum.TECHNICIENS_AGENTS_MAITRISES; écarts: number | null },
-          { nom: CSP.Enum.INGENIEURS_CADRES; écarts: number | null },
-        ];
+        catégories: {
+          [CSP.Enum.OUVRIERS]: number | "";
+          [CSP.Enum.EMPLOYES]: number | "";
+          [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: number | "";
+          [CSP.Enum.INGENIEURS_CADRES]: number | "";
+        };
         estCalculable: "oui";
         note: number;
-        populationFavorable: FavorablePopulation.Enum;
+        populationFavorable?: FavorablePopulationEnum;
         résultat: number;
       }
     | {
@@ -93,7 +95,7 @@ export type DeclarationDTO = {
         note: number;
         noteNombreSalaries: number;
         notePourcentage: number;
-        populationFavorable: FavorablePopulation.Enum;
+        populationFavorable?: FavorablePopulationEnum;
         résultat: number;
         résultatEquivalentSalarié: number;
       };
@@ -126,7 +128,7 @@ export type DeclarationDTO = {
   entreprise?: { entrepriseDéclarante?: Entreprise; tranche?: CompanyWorkforceRange.Enum; type?: "entreprise" | "ues" };
   "hautes-remunerations"?: {
     note: number;
-    populationFavorable: FavorablePopulation.Enum;
+    populationFavorable?: FavorablePopulationEnum;
     résultat: number;
   };
   "periode-reference"?:
@@ -140,15 +142,15 @@ export type DeclarationDTO = {
       };
   promotions?:
     | {
-        catégories: [
-          { nom: "ouv"; écarts: number | null },
-          { nom: "emp"; écarts: number | null },
-          { nom: "tam"; écarts: number | null },
-          { nom: "ic"; écarts: number | null },
-        ];
+        catégories: {
+          [CSP.Enum.OUVRIERS]: number | "";
+          [CSP.Enum.EMPLOYES]: number | "";
+          [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: number | "";
+          [CSP.Enum.INGENIEURS_CADRES]: number | "";
+        };
         estCalculable: "oui";
         note: number;
-        populationFavorable: FavorablePopulation.Enum;
+        populationFavorable?: FavorablePopulationEnum;
         résultat: number;
       }
     | {
@@ -195,7 +197,7 @@ export type DeclarationDTO = {
   };
   "remunerations-resultat"?: {
     note: number;
-    populationFavorable: FavorablePopulation.Enum;
+    populationFavorable?: FavorablePopulationEnum;
     résultat: number;
   };
   "resultat-global"?: {
diff --git a/packages/app/src/common/core-domain/mappers/declarationMap.ts b/packages/app/src/common/core-domain/mappers/declarationMap.ts
index 6d30fb5a3..a8a79694f 100644
--- a/packages/app/src/common/core-domain/mappers/declarationMap.ts
+++ b/packages/app/src/common/core-domain/mappers/declarationMap.ts
@@ -17,6 +17,7 @@ import { omitByRecursively } from "@common/utils/object";
 import { type Any } from "@common/utils/types";
 import { isUndefined } from "lodash";
 
+import { toBinaryFavorablePopulation } from "../computers/DeclarationComputer";
 import { Declaration } from "../domain/Declaration";
 import { CSP } from "../domain/valueObjects/CSP";
 import { AgeRange } from "../domain/valueObjects/declaration/AgeRange";
@@ -258,13 +259,13 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
           estCalculable: "oui",
           note: salaryRaises.score?.getValue() ?? 0,
           résultat: salaryRaises.result?.getValue() ?? 0,
-          populationFavorable: salaryRaises.favorablePopulation?.getValue() ?? FavorablePopulation.Enum.EQUALITY,
-          catégories: [
-            { nom: CSP.Enum.OUVRIERS, écarts: salaryRaises.categories[0]?.getValue() || null },
-            { nom: CSP.Enum.EMPLOYES, écarts: salaryRaises.categories[1]?.getValue() || null },
-            { nom: CSP.Enum.TECHNICIENS_AGENTS_MAITRISES, écarts: salaryRaises.categories[2]?.getValue() || null },
-            { nom: CSP.Enum.INGENIEURS_CADRES, écarts: salaryRaises.categories[3]?.getValue() || null },
-          ],
+          populationFavorable: toBinaryFavorablePopulation(salaryRaises.favorablePopulation!.getValue()),
+          catégories: {
+            [CSP.Enum.OUVRIERS]: salaryRaises.categories[0]?.getValue() || "",
+            [CSP.Enum.EMPLOYES]: salaryRaises.categories[1]?.getValue() || "",
+            [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: salaryRaises.categories[2]?.getValue() || "",
+            [CSP.Enum.INGENIEURS_CADRES]: salaryRaises.categories[3]?.getValue() || "",
+          },
         };
       }
     }
@@ -281,13 +282,13 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
           estCalculable: "oui",
           note: promotions.score?.getValue() ?? 0,
           résultat: promotions.result?.getValue() ?? 0,
-          populationFavorable: promotions.favorablePopulation?.getValue() ?? FavorablePopulation.Enum.EQUALITY,
-          catégories: [
-            { nom: "ouv", écarts: promotions?.categories?.[0]?.getValue() ?? null },
-            { nom: "emp", écarts: promotions?.categories?.[1]?.getValue() ?? null },
-            { nom: "tam", écarts: promotions?.categories?.[2]?.getValue() ?? null },
-            { nom: "ic", écarts: promotions?.categories?.[3]?.getValue() ?? null },
-          ],
+          populationFavorable: toBinaryFavorablePopulation(promotions.favorablePopulation!.getValue()),
+          catégories: {
+            [CSP.Enum.OUVRIERS]: promotions.categories[0]?.getValue() || "",
+            [CSP.Enum.EMPLOYES]: promotions.categories[1]?.getValue() || "",
+            [CSP.Enum.TECHNICIENS_AGENTS_MAITRISES]: promotions.categories[2]?.getValue() || "",
+            [CSP.Enum.INGENIEURS_CADRES]: promotions.categories[3]?.getValue() || "",
+          },
         };
       }
     }
@@ -305,8 +306,7 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
           note: salaryRaisesAndPromotions.score?.getValue() ?? 0,
           noteNombreSalaries: salaryRaisesAndPromotions.employeesCountScore?.getValue() ?? 0,
           notePourcentage: salaryRaisesAndPromotions.percentScore?.getValue() ?? 0,
-          populationFavorable:
-            salaryRaisesAndPromotions.favorablePopulation?.getValue() ?? FavorablePopulation.Enum.EQUALITY,
+          populationFavorable: toBinaryFavorablePopulation(salaryRaisesAndPromotions.favorablePopulation!.getValue()),
           résultat: salaryRaisesAndPromotions.result?.getValue() ?? 0,
           résultatEquivalentSalarié: salaryRaisesAndPromotions.employeesCountResult?.getValue() ?? 0,
         };
@@ -317,7 +317,7 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
     if (remunerations) {
       dto["remunerations-resultat"] = {
         note: remunerations.score?.getValue() ?? 0,
-        populationFavorable: remunerations.favorablePopulation?.getValue() ?? FavorablePopulation.Enum.EQUALITY,
+        populationFavorable: toBinaryFavorablePopulation(remunerations.favorablePopulation!.getValue()),
         résultat: remunerations.result?.getValue() ?? 0,
       };
 
@@ -349,10 +349,10 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
         catégories: remunerations?.categories.map(category => ({
           nom: category.name || "",
           tranches: {
-            [AgeRange.Enum.LESS_THAN_30]: category.ranges?.[":29"]?.getValue() || null,
-            [AgeRange.Enum.FROM_30_TO_39]: category.ranges?.["30:39"]?.getValue() || null,
-            [AgeRange.Enum.FROM_40_TO_49]: category.ranges?.["40:49"]?.getValue() || null,
-            [AgeRange.Enum.FROM_50_TO_MORE]: category.ranges?.["50:"]?.getValue() || null,
+            [AgeRange.Enum.LESS_THAN_30]: category.ranges?.[":29"]?.getValue() || "",
+            [AgeRange.Enum.FROM_30_TO_39]: category.ranges?.["30:39"]?.getValue() || "",
+            [AgeRange.Enum.FROM_40_TO_49]: category.ranges?.["40:49"]?.getValue() || "",
+            [AgeRange.Enum.FROM_50_TO_MORE]: category.ranges?.["50:"]?.getValue() || "",
           },
         })),
       };
@@ -363,10 +363,10 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
         catégories: remunerations?.categories.map(category => ({
           nom: category.name || "",
           tranches: {
-            [AgeRange.Enum.LESS_THAN_30]: category.ranges?.[":29"]?.getValue() || null,
-            [AgeRange.Enum.FROM_30_TO_39]: category.ranges?.["30:39"]?.getValue() || null,
-            [AgeRange.Enum.FROM_40_TO_49]: category.ranges?.["40:49"]?.getValue() || null,
-            [AgeRange.Enum.FROM_50_TO_MORE]: category.ranges?.["50:"]?.getValue() || null,
+            [AgeRange.Enum.LESS_THAN_30]: category.ranges?.[":29"]?.getValue() || "",
+            [AgeRange.Enum.FROM_30_TO_39]: category.ranges?.["30:39"]?.getValue() || "",
+            [AgeRange.Enum.FROM_40_TO_49]: category.ranges?.["40:49"]?.getValue() || "",
+            [AgeRange.Enum.FROM_50_TO_MORE]: category.ranges?.["50:"]?.getValue() || "",
           },
         })),
       };
@@ -378,37 +378,37 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
           {
             nom: "ouv",
             tranches: {
-              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[0].ranges?.[":29"]?.getValue() || null,
-              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[0].ranges?.["30:39"]?.getValue() || null,
-              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[0].ranges?.["40:49"]?.getValue() || null,
-              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[0].ranges?.["50:"]?.getValue() || null,
+              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[0].ranges?.[":29"]?.getValue() || "",
+              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[0].ranges?.["30:39"]?.getValue() || "",
+              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[0].ranges?.["40:49"]?.getValue() || "",
+              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[0].ranges?.["50:"]?.getValue() || "",
             },
           },
           {
             nom: "emp",
             tranches: {
-              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[1].ranges?.[":29"]?.getValue() || null,
-              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[1].ranges?.["30:39"]?.getValue() || null,
-              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[1].ranges?.["40:49"]?.getValue() || null,
-              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[1].ranges?.["50:"]?.getValue() || null,
+              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[1].ranges?.[":29"]?.getValue() || "",
+              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[1].ranges?.["30:39"]?.getValue() || "",
+              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[1].ranges?.["40:49"]?.getValue() || "",
+              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[1].ranges?.["50:"]?.getValue() || "",
             },
           },
           {
             nom: "tam",
             tranches: {
-              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[2].ranges?.[":29"]?.getValue() || null,
-              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[2].ranges?.["30:39"]?.getValue() || null,
-              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[2].ranges?.["40:49"]?.getValue() || null,
-              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[2].ranges?.["50:"]?.getValue() || null,
+              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[2].ranges?.[":29"]?.getValue() || "",
+              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[2].ranges?.["30:39"]?.getValue() || "",
+              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[2].ranges?.["40:49"]?.getValue() || "",
+              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[2].ranges?.["50:"]?.getValue() || "",
             },
           },
           {
             nom: "ic",
             tranches: {
-              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[3].ranges?.[":29"]?.getValue() || null,
-              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[3].ranges?.["30:39"]?.getValue() || null,
-              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[3].ranges?.["40:49"]?.getValue() || null,
-              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[3].ranges?.["50:"]?.getValue() || null,
+              [AgeRange.Enum.LESS_THAN_30]: remunerations.categories[3].ranges?.[":29"]?.getValue() || "",
+              [AgeRange.Enum.FROM_30_TO_39]: remunerations.categories[3].ranges?.["30:39"]?.getValue() || "",
+              [AgeRange.Enum.FROM_40_TO_49]: remunerations.categories[3].ranges?.["40:49"]?.getValue() || "",
+              [AgeRange.Enum.FROM_50_TO_MORE]: remunerations.categories[3].ranges?.["50:"]?.getValue() || "",
             },
           },
         ],
@@ -435,7 +435,7 @@ export const declarationMap: Required<Mapper<Declaration, DeclarationDTO, Declar
     if (highRemunerations) {
       dto["hautes-remunerations"] = {
         note: obj.highRemunerations!.score.getValue(),
-        populationFavorable: obj.highRemunerations!.favorablePopulation.getValue(),
+        populationFavorable: toBinaryFavorablePopulation(obj.highRemunerations!.favorablePopulation.getValue()),
         résultat: obj.highRemunerations!.result.getValue(),
       };
     }
diff --git a/packages/app/src/common/utils/form.ts b/packages/app/src/common/utils/form.ts
index e148cb160..7c375e59a 100644
--- a/packages/app/src/common/utils/form.ts
+++ b/packages/app/src/common/utils/form.ts
@@ -3,12 +3,13 @@ import { Email } from "@common/shared-domain/domain/valueObjects";
 import { isValid, parseISO } from "date-fns";
 import { z } from "zod";
 
+import { INVALID_SIREN, MANDATORY_SIREN } from "../../app/(default)/messages";
 import { zodValueObjectSuperRefine } from "./zod";
 
 export const zodSirenSchema = z
   .string()
-  .min(1, { message: "Le Siren est requis." })
-  .regex(/^[0-9]{9}$/, "Le Siren est formé de 9 chiffres.");
+  .min(1, { message: MANDATORY_SIREN })
+  .regex(/^[0-9]{9}$/, INVALID_SIREN);
 
 // TODO: make 2020 a constant or better, fetch the authorized years in /config endpoint (see useConfig).
 export const zodYearSchema = z
@@ -59,6 +60,14 @@ export const zodNumberOrNaNOrNull = z
   .null()
   .or(z.nan().or(z.number({ invalid_type_error: "La valeur doit être un nombre" })));
 
+export const zodNumberOrEmptyString = z
+  .literal("", {
+    errorMap: () => ({
+      message: "La valeur est obligatoire ",
+    }),
+  })
+  .or(z.number({ invalid_type_error: "La valeur doit être un nombre" }));
+
 export const zodNumberOrNull = z.null().or(z.number({ invalid_type_error: "La valeur doit être un nombre" }));
 
 export const zodPercentOrNaNOrNull = z
diff --git a/packages/app/src/components/RHF/IndicatorNote.module.css b/packages/app/src/components/RHF/IndicatorNote.module.css
new file mode 100644
index 000000000..2826a892d
--- /dev/null
+++ b/packages/app/src/components/RHF/IndicatorNote.module.css
@@ -0,0 +1,74 @@
+.tile:not(.tile-no-border),
+.tile-small:not(.tile-no-border) {
+    box-shadow: 0 0 0 1px var(--border-default-grey);
+}
+
+.tile {
+    padding: 1rem 2rem;
+}
+
+.tile-small {
+    padding: .75rem 2rem;
+}
+
+.tile-note,
+.tile-content {
+    display: flex;
+}
+
+.text {
+    color: var(--text-title-grey);
+}
+
+.note,
+.note-small {
+    font-weight: 700;
+    line-height: 1;
+}
+
+.note {
+    font-size: 2rem;
+}
+
+.note-small {
+    font-size: 1.375rem;
+}
+
+.max {
+    font-size: 0.875rem;
+    font-weight: 200;
+    transform: translateY(0.313rem);
+}
+
+@media (max-width: 35.938rem) {
+    .tile-note {
+        padding-top: .5rem;
+        justify-content: center;
+    }
+    .tile-content {
+        padding-top: .5rem;
+        flex-direction: column;
+        align-items: center;
+    }
+}
+
+@media (min-width: 36em) {
+    .tile,
+    .tile-small {
+        display: flex;
+        align-items: stretch;
+    }
+    .tile-note {
+        flex-shrink: 0;
+        border-right: 1px solid var(--border-default-grey);
+        padding-right: 1rem;
+        align-items: center;
+    }
+    .tile-content {
+        flex-grow: 1;
+        flex-direction: column;
+        justify-content: center;
+        padding-left: 1rem;
+    }
+}
+
diff --git a/packages/app/src/components/RHF/IndicatorNoteInput.tsx b/packages/app/src/components/RHF/IndicatorNoteInput.tsx
new file mode 100644
index 000000000..9900e8517
--- /dev/null
+++ b/packages/app/src/components/RHF/IndicatorNoteInput.tsx
@@ -0,0 +1,67 @@
+import { fr } from "@codegouvfr/react-dsfr";
+import { cx } from "@codegouvfr/react-dsfr/tools/cx";
+import { type ReactNode, useEffect } from "react";
+import { useFormContext } from "react-hook-form";
+
+import styles from "./IndicatorNote.module.css";
+
+type BaseIndicatorNoteProps = {
+  className?: string;
+  classes?: Partial<Record<"content" | "description" | "legend" | "max" | "note" | "root" | "text", string>>;
+  name?: string;
+  noBorder?: boolean;
+  size?: "large" | "small";
+  text: NonNullable<ReactNode>;
+};
+
+type LargeIndicatorNoteProps = BaseIndicatorNoteProps & {
+  max?: number;
+  size?: "large";
+};
+
+type SmallIndicatorNoteProps = BaseIndicatorNoteProps & {
+  max?: never;
+  size?: "small";
+};
+
+type IndicatorNoteProps = LargeIndicatorNoteProps | SmallIndicatorNoteProps;
+
+export const IndicatorNoteInput = ({
+  name = "note",
+  noBorder,
+  max,
+  text,
+  className,
+  size = "large",
+  classes = {},
+}: IndicatorNoteProps) => {
+  const { register, getValues } = useFormContext();
+
+  useEffect(() => {
+    register("note");
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  return (
+    <div
+      className={cx(
+        size === "small" ? styles["tile-small"] : styles.tile,
+        noBorder && styles["tile-no-border"],
+        classes.root,
+        className,
+      )}
+    >
+      <div className={styles["tile-note"]}>
+        <span className={cx(size === "small" ? styles["note-small"] : styles["note"], classes.note)}>
+          {getValues(name)}
+        </span>
+        {size === "large" && typeof max === "number" && (
+          <span className={cx(styles.max, classes.max)}>&nbsp;/&nbsp;{max}</span>
+        )}
+      </div>
+      <div className={cx(styles["tile-content"], classes.content)}>
+        <p className={cx(fr.cx("fr-m-0"), styles.text, classes.text)}>{text}</p>
+      </div>
+    </div>
+  );
+};
diff --git a/packages/app/src/components/RHF/PercentageInput.tsx b/packages/app/src/components/RHF/PercentageInput.tsx
index dc6908234..a58c93c6e 100644
--- a/packages/app/src/components/RHF/PercentageInput.tsx
+++ b/packages/app/src/components/RHF/PercentageInput.tsx
@@ -16,6 +16,15 @@ type FakeFormType = {
 };
 type FakeKey = keyof FakeFormType;
 
+/**
+ * PercentageInput is a wrapper around Input to handle percentage input.
+ *
+ * It stores the data as a number and "" for empty input.
+ * It is so because React doesn't advise to use null or undefined for input value.
+ *
+ * @param param0
+ * @returns
+ */
 export const PercentageInput = <FormType extends SimpleObject>({
   label,
   min,
@@ -40,20 +49,21 @@ export const PercentageInput = <FormType extends SimpleObject>({
           type: "number",
           min,
           max,
+          defaultValue: "",
           step: 0.1,
           ...register(name, {
             setValueAs: (value: string | null) => {
-              // We implement our own valueAsNumber because valueAsNumber returns NaN for empty string and we want null instead for consistency.
-              if (value === null) return null;
-              const num = Number(value);
-              return isNaN(num) || value === "" ? null : num;
+              // We implement our own valueAsNumber because valueAsNumber returns null for empty input and we need "" for React to be safe.
+              if (value === null) return "";
+              const num = Number.parseFloat(value);
+              return isNaN(num) ? "" : num;
             },
             disabled,
           }),
           onBlur: e => {
             // Round number to 1 decimal.
-            const num = Number(e.target.value);
-            if (!isNaN(num) && e.target.value !== "") {
+            const num = Number.parseFloat(e.target.value);
+            if (!isNaN(num)) {
               setValue(name, Math.round(num * 10) / 10);
             }
           },
diff --git a/packages/app/src/components/RHF/PopulationFavorable.tsx b/packages/app/src/components/RHF/PopulationFavorable.tsx
index 05f2ca56e..b1a823712 100644
--- a/packages/app/src/components/RHF/PopulationFavorable.tsx
+++ b/packages/app/src/components/RHF/PopulationFavorable.tsx
@@ -1,4 +1,5 @@
 import RadioButtons from "@codegouvfr/react-dsfr/RadioButtons";
+import { FavorablePopulation } from "@common/core-domain/domain/valueObjects/declaration/indicators/FavorablePopulation";
 import { get } from "lodash";
 import { useFormContext } from "react-hook-form";
 
@@ -19,16 +20,16 @@ export const PopulationFavorable = ({ legend, disabled }: Props) => {
       disabled={disabled}
       options={[
         {
-          label: "Femmes",
+          label: FavorablePopulation.Label[FavorablePopulation.Enum.WOMEN],
           nativeInputProps: {
-            value: "femmes",
+            value: FavorablePopulation.Enum.WOMEN,
             ...register("populationFavorable"),
           },
         },
         {
-          label: "Hommes",
+          label: FavorablePopulation.Label[FavorablePopulation.Enum.MEN],
           nativeInputProps: {
-            value: "hommes",
+            value: FavorablePopulation.Enum.MEN,
             ...register("populationFavorable"),
           },
         },