diff --git a/docs/spec/components/schemas/User.yaml b/docs/spec/components/schemas/User.yaml
index d526895..656a4a5 100644
--- a/docs/spec/components/schemas/User.yaml
+++ b/docs/spec/components/schemas/User.yaml
@@ -6,10 +6,6 @@ allOf:
       - attributes
     properties:
       attributes:
-        required:
-          - age_lower_bound
-          - uniqueness
-          - nationality
         properties:
           age_lower_bound:
             type: integer
diff --git a/internal/assets/migrations/001_initial.sql b/internal/assets/migrations/001_initial.sql
index 8d57086..c5a35b4 100644
--- a/internal/assets/migrations/001_initial.sql
+++ b/internal/assets/migrations/001_initial.sql
@@ -4,11 +4,11 @@ CREATE TABLE verify_users
 (
     user_id         TEXT PRIMARY KEY NOT NULL,
     user_id_hash    TEXT             NOT NULL,
-    age_lower_bound INT              NOT NULL,
-    nationality     TEXT             NOT NULL,
+    age_lower_bound INT,
+    nationality     TEXT,
     created_at      TIMESTAMP        NOT NULL DEFAULT (NOW() AT TIME ZONE 'utc'),
     uniqueness      BOOLEAN          NOT NULL,
-    event_id        TEXT             NOT NULL,
+    event_id        TEXT,
     status          TEXT             NOT NULL,
     proof           JSON             NOT NULL
 );
diff --git a/internal/config/verifier.go b/internal/config/verifier.go
index 96610c4..2f9f0f3 100644
--- a/internal/config/verifier.go
+++ b/internal/config/verifier.go
@@ -32,7 +32,6 @@ func (c *config) Verifiers() Verifiers {
 			zk.WithVerificationKeyFile(cfg.VerificationKeyPath),
 			zk.WithPassportRootVerifier(c.passport.ProvideVerifier()),
 			zk.WithIdentitiesCreationTimestampLimit(cfg.AllowedIdentityTimestamp),
-			zk.WithEventID(c.ProofParametersConfig().EventID),
 		)
 		if err != nil {
 			panic(fmt.Errorf("failed to initialize passport verifier: %w", err))
diff --git a/internal/service/handlers/get_proof.go b/internal/service/handlers/get_proof.go
index 02a03d5..ddcea00 100644
--- a/internal/service/handlers/get_proof.go
+++ b/internal/service/handlers/get_proof.go
@@ -44,7 +44,7 @@ func NewProofByUserIDResponse(user data.VerifyUsers) resources.GetProofRequest {
 				Type: resources.GET_PROOF,
 			},
 			Attributes: resources.GetProofAttributes{
-				Proof: &proof,
+				Proof: proof,
 			},
 		},
 	}
diff --git a/internal/service/handlers/proof_params.go b/internal/service/handlers/proof_params.go
index 5939faf..caabe69 100644
--- a/internal/service/handlers/proof_params.go
+++ b/internal/service/handlers/proof_params.go
@@ -47,6 +47,11 @@ func GetProofParamsById(w http.ResponseWriter, r *http.Request) {
 		eventID = existingUser.EventId
 	}
 
+	birthDateUpperBound := CalculateBirthDateHex(existingUser.AgeLowerBound)
+	if existingUser.AgeLowerBound == 0 {
+		birthDateUpperBound = "0x303030303030"
+	}
+
 	proofSelector := CalculateProofSelector(existingUser.Uniqueness)
 	if proofSelector&(1<<timestampUpperBoundBit) != 0 &&
 		proofSelector&(1<<identityCounterUpperBoundBit) != 0 {
@@ -62,7 +67,7 @@ func GetProofParamsById(w http.ResponseWriter, r *http.Request) {
 		citizenshipMask:           Utf8ToHex(existingUser.Nationality),
 		timestampLowerBound:       "0",
 		birthDateLowerBound:       "0x303030303030",
-		birthDateUpperBound:       CalculateBirthDateHex(existingUser.AgeLowerBound),
+		birthDateUpperBound:       birthDateUpperBound,
 		expirationDateUpperBound:  "52983525027888",
 		expirationDateLowerBound:  "52983525027888",
 	}
diff --git a/internal/service/handlers/verification-link.go b/internal/service/handlers/verification-link.go
index 523c7b1..ab8ddca 100644
--- a/internal/service/handlers/verification-link.go
+++ b/internal/service/handlers/verification-link.go
@@ -26,15 +26,29 @@ func VerificationLink(w http.ResponseWriter, r *http.Request) {
 	}
 
 	user := &data.VerifyUsers{
-		UserID:        req.Data.ID,
-		UserIDHash:    userIdHash,
-		CreatedAt:     time.Now().UTC(),
-		Status:        "not_verified",
-		Nationality:   req.Data.Attributes.Nationality,
-		EventId:       req.Data.Attributes.EventId,
-		AgeLowerBound: int(req.Data.Attributes.AgeLowerBound),
-		Uniqueness:    req.Data.Attributes.Uniqueness,
-		Proof:         []byte{},
+		UserID:     req.Data.ID,
+		UserIDHash: userIdHash,
+		CreatedAt:  time.Now().UTC(),
+		Status:     "not_verified",
+		Proof:      []byte{},
+	}
+
+	if req.Data.Attributes.Nationality != nil && *req.Data.Attributes.Nationality != "" {
+		user.Nationality = *req.Data.Attributes.Nationality
+	}
+
+	if req.Data.Attributes.EventId != nil && *req.Data.Attributes.EventId != "" {
+		user.EventId = *req.Data.Attributes.EventId
+	}
+
+	if req.Data.Attributes.AgeLowerBound != nil {
+		user.AgeLowerBound = int(*req.Data.Attributes.AgeLowerBound)
+	}
+
+	if req.Data.Attributes.Uniqueness != nil {
+		user.Uniqueness = *req.Data.Attributes.Uniqueness
+	} else {
+		user.Uniqueness = false
 	}
 
 	existingUser, err := VerifyUsersQ(r).WhereHashID(user.UserIDHash).Get()
diff --git a/internal/service/handlers/verification_callback.go b/internal/service/handlers/verification_callback.go
index b2a67b8..c335235 100644
--- a/internal/service/handlers/verification_callback.go
+++ b/internal/service/handlers/verification_callback.go
@@ -58,6 +58,11 @@ func VerificationCallback(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	eventID := ProofParameters(r).EventID
+	if verifiedUser.EventId != "" {
+		eventID = verifiedUser.EventId
+	}
+
 	selectorInt, err := strconv.Atoi(getter.Get(zk.Selector))
 	if err != nil {
 		Log(r).WithError(err).Errorf("cannot extract selector from public signals")
@@ -97,8 +102,9 @@ func VerificationCallback(w http.ResponseWriter, r *http.Request) {
 		zk.WithProofSelectorValue(getter.Get(zk.Selector)),
 		zk.WithIdentitiesCounter(identityCounterUpperBound),
 		zk.WithAgeAbove(verifiedUser.AgeLowerBound),
+		zk.WithEventID(eventID),
 	}
-	err = Verifiers(r).Passport.VerifyProof(*proof, verifyOpts...)
+	err = Verifiers(r).Passport.VerifyProof(proof, verifyOpts...)
 	if err != nil {
 		var vErr validation.Errors
 		if errors.As(err, &vErr) {
diff --git a/internal/service/requests/verification-link.go b/internal/service/requests/verification-link.go
index 5c69400..11ed9ed 100644
--- a/internal/service/requests/verification-link.go
+++ b/internal/service/requests/verification-link.go
@@ -21,8 +21,8 @@ func VerificationLink(r *http.Request) (req resources.UserRequest, err error) {
 	return req, val.Errors{
 		"data/id":                         val.Validate(req.Data.ID, val.Required),
 		"data/type":                       val.Validate(req.Data.Type, val.Required, val.In(resources.USER)),
-		"data/attributes/age_lower_bound": val.Validate(attr.AgeLowerBound, val.Required),
-		"data/attributes/nationality":     val.Validate(attr.Nationality, val.Required),
-		"data/attributes/event_id":        val.Validate(attr.Nationality, val.Required),
+		"data/attributes/age_lower_bound": val.Validate(attr.AgeLowerBound),
+		"data/attributes/nationality":     val.Validate(attr.Nationality),
+		"data/attributes/event_id":        val.Validate(attr.EventId),
 	}.Filter()
 }
diff --git a/resources/model_get_proof_attributes.go b/resources/model_get_proof_attributes.go
index 94d7752..5eeb100 100644
--- a/resources/model_get_proof_attributes.go
+++ b/resources/model_get_proof_attributes.go
@@ -8,5 +8,5 @@ import "github.com/iden3/go-rapidsnark/types"
 
 type GetProofAttributes struct {
 	// Query ZK passport verification proof.
-	Proof *types.ZKProof `json:"proof"`
+	Proof types.ZKProof `json:"proof"`
 }
diff --git a/resources/model_proof_attributes.go b/resources/model_proof_attributes.go
index 79e6c75..0712853 100644
--- a/resources/model_proof_attributes.go
+++ b/resources/model_proof_attributes.go
@@ -8,5 +8,5 @@ import "github.com/iden3/go-rapidsnark/types"
 
 type ProofAttributes struct {
 	// Query ZK passport verification proof.
-	Proof *types.ZKProof `json:"proof"`
+	Proof types.ZKProof `json:"proof"`
 }
diff --git a/resources/model_user_attributes.go b/resources/model_user_attributes.go
index 14cd73a..62121a8 100644
--- a/resources/model_user_attributes.go
+++ b/resources/model_user_attributes.go
@@ -5,8 +5,8 @@
 package resources
 
 type UserAttributes struct {
-	AgeLowerBound int32  `json:"age_lower_bound"`
-	EventId       string `json:"event_id,omitempty"`
-	Nationality   string `json:"nationality"`
-	Uniqueness    bool   `json:"uniqueness"`
+	AgeLowerBound *int32  `json:"age_lower_bound,omitempty"`
+	EventId       *string `json:"event_id,omitempty"`
+	Nationality   *string `json:"nationality,omitempty"`
+	Uniqueness    *bool   `json:"uniqueness,omitempty"`
 }