diff --git a/apps/admin-ui/src/component/ReservationTypeForm.tsx b/apps/admin-ui/src/component/ReservationTypeForm.tsx
index c763acd246..fbf41d0a88 100644
--- a/apps/admin-ui/src/component/ReservationTypeForm.tsx
+++ b/apps/admin-ui/src/component/ReservationTypeForm.tsx
@@ -105,10 +105,12 @@ function ReservationTypeForm({
   reservationUnit,
   children,
   disableBufferToggle,
+  disableTypeSelect,
 }: {
   reservationUnit: TypeFormReservationUnit;
   children?: React.ReactNode;
   disableBufferToggle?: boolean;
+  disableTypeSelect?: boolean;
 }) {
   const { t } = useTranslation();
 
@@ -121,7 +123,7 @@ function ReservationTypeForm({
   return (
     <>
       <Element $wide>
-        <TypeSelect />
+        <TypeSelect isDisabled={disableTypeSelect} />
       </Element>
       {type === ReservationTypeChoice.Blocked && (
         <CommentsTextArea
diff --git a/apps/admin-ui/src/i18n/messages.ts b/apps/admin-ui/src/i18n/messages.ts
index 151688c4a4..fd195682ed 100644
--- a/apps/admin-ui/src/i18n/messages.ts
+++ b/apps/admin-ui/src/i18n/messages.ts
@@ -221,6 +221,7 @@ const translations: ITranslations = {
       RESERVATION_END_DATE_TOO_FAR: [
         "Ei pystytty luomaan varauksia yli 2 vuoden päähän",
       ],
+      RESERVATION_SERIES_ALREADY_STARTED: ["Toistuva varaus on jo alkanut"],
     },
     descriptive: {
       "Reservation overlaps with reservation before due to buffer time.": [
diff --git a/apps/admin-ui/src/schemas/recurringReservation.ts b/apps/admin-ui/src/schemas/recurringReservation.ts
index bfd4f576c7..f6477fba09 100644
--- a/apps/admin-ui/src/schemas/recurringReservation.ts
+++ b/apps/admin-ui/src/schemas/recurringReservation.ts
@@ -135,9 +135,7 @@ const RescheduleReservationSeriesFormSchemaRefined = (
     // TODO do we need it here? reschedule might not have metadata
     .passthrough()
     // this refine works without partial since it's the last required value
-    .superRefine((val, ctx) =>
-      checkDateNotInPast(convertToDate(val.startingDate), ctx, "startingDate")
-    )
+    /* Don't validate start time since it's not editable */
     .superRefine((val, ctx) =>
       checkDateNotInPast(convertToDate(val.endingDate), ctx, "endingDate")
     )
diff --git a/apps/admin-ui/src/spa/reservations/[id]/edit.tsx b/apps/admin-ui/src/spa/reservations/[id]/edit.tsx
index d7dcaf4db8..de2a2e2dff 100644
--- a/apps/admin-ui/src/spa/reservations/[id]/edit.tsx
+++ b/apps/admin-ui/src/spa/reservations/[id]/edit.tsx
@@ -179,6 +179,8 @@ function EditReservation({
         <ReservationTypeForm
           reservationUnit={reservationUnit}
           disableBufferToggle
+          // backend doesn't allow changing type for series but does allow it for single reservations
+          disableTypeSelect={reservation.recurringReservation?.pk != null}
         >
           {reservation.recurringReservation?.pk && (
             <InnerTextInput
diff --git a/apps/admin-ui/src/spa/reservations/[id]/series/index.tsx b/apps/admin-ui/src/spa/reservations/[id]/series/index.tsx
index 067ea6fbb5..28c8719c28 100644
--- a/apps/admin-ui/src/spa/reservations/[id]/series/index.tsx
+++ b/apps/admin-ui/src/spa/reservations/[id]/series/index.tsx
@@ -317,6 +317,8 @@ function SeriesPageInner({ pk }: { pk: number }) {
                 control={control}
                 error={translateError(errors.startingDate?.message)}
                 required
+                // NOTE we can't change the start date of the series
+                disabled
               />
 
               <ControlledDateInput