diff --git a/crates/dpp-vault/src/domain/service/create.rs b/crates/dpp-vault/src/domain/service/create.rs
index 4b523444..993d943e 100644
--- a/crates/dpp-vault/src/domain/service/create.rs
+++ b/crates/dpp-vault/src/domain/service/create.rs
@@ -418,6 +418,41 @@ pub(super) fn apply_patch(
             .map_err(|e| DppError::Validation(format!("invalid productGroupData: {e}").into()))?;
         dpp_domain::validate_product_group_data(&product_group_data)
             .map_err(DppError::Validation)?;
+
+        // 🚨 **The second door to a mislabelled passport, and it is open wider
+        // than the first.**
+        //
+        // `productGroupData` is patchable and `productGroup` is not, so without
+        // this a `PUT` on a draft swaps in another product group's payload while
+        // the protected label stays exactly as it was — reaching the same state
+        // the create path refuses, by a route that never has to state a product
+        // group at all.
+        //
+        // It matters because the label is what picks the disclosure table at
+        // publish. A payload whose fields the label's table does not name falls
+        // to `default_disclosure`, which is `Public` — so textile data under a
+        // battery label publishes the REACH Art. 33 substance declarations that
+        // textile's own table marks `restricted`, signed into
+        // `publicJwsSignature`.
+        //
+        // Refusing rather than re-labelling: `product_group` is protected
+        // precisely because it is not a caller's to change after creation, and
+        // quietly moving it here would route around that on the one path that
+        // does not name it.
+        if product_group_data.product_group() != passport.product_group {
+            return Err(DppError::Validation(
+                format!(
+                    "productGroupData is `{}` and this passport is `{}`. The product group is \
+                     fixed at creation and selects the disclosure table the public view is \
+                     filtered and signed under, so it cannot be changed by patching the payload \
+                     underneath it.",
+                    product_group_data.product_group().catalog_key(),
+                    passport.product_group.catalog_key()
+                )
+                .into(),
+            ));
+        }
+
         passport.product_group_data = Some(product_group_data);
         applied.push("productGroupData");
     }
@@ -807,6 +842,48 @@ mod tests {
         assert!(matches!(err, DppError::Validation(_)));
     }
 
+    /// 🚨 A patch cannot move a passport to another product group's payload.
+    ///
+    /// `productGroupData` is in `PATCHABLE_FIELDS` and `productGroup` is not, so
+    /// without this a `PUT` on a draft swaps in another group's payload while the
+    /// protected label stays exactly as it was — the same mislabelled state the
+    /// create path refuses, reached by a route that never names a product group.
+    ///
+    /// It matters because the **label** picks the disclosure table at publish. A
+    /// payload field the label's table does not name falls to
+    /// `default_disclosure`, which is `Public` — so textile data under a battery
+    /// label publishes the REACH Art. 33 substance declarations textile's own
+    /// table marks `restricted`, signed into `publicJwsSignature`.
+    #[test]
+    fn a_patch_may_not_change_the_product_group_under_the_label() {
+        let mut p = stub();
+        assert_eq!(
+            p.product_group,
+            ProductGroup::Battery,
+            "the stub is battery"
+        );
+
+        let err = apply_patch(
+            &mut p,
+            &serde_json::json!({"productGroupData": {
+                "productGroup": "textile",
+                "gtin": "09506000134352",
+                "fibreComposition": [{ "fibre": "cotton", "pct": 100.0 }],
+                "careInstructions": "wash cold",
+                "countryOfOrigin": "PT",
+                "chemicalComplianceStandard": "oeko-tex-100",
+            }}),
+        )
+        .unwrap_err();
+
+        assert!(matches!(err, DppError::Validation(_)), "{err:?}");
+        assert_eq!(
+            p.product_group,
+            ProductGroup::Battery,
+            "and the label is untouched — the refusal must not half-apply"
+        );
+    }
+
     #[test]
     fn patch_empty_object_is_noop() {
         let mut p = stub();
diff --git a/crates/dpp-vault/src/handlers/create.rs b/crates/dpp-vault/src/handlers/create.rs
index e76d8f88..e5e63276 100644
--- a/crates/dpp-vault/src/handlers/create.rs
+++ b/crates/dpp-vault/src/handlers/create.rs
@@ -687,6 +687,45 @@ pub fn validate_create_request(body: &CreatePassportRequest) -> Option<axum::res
     // typed product group data, else Other. Derived again here rather than passed in —
     // it is pure, and computing it locally keeps this function callable on a
     // bare request body with nothing else in hand.
+    // 🚨 **The two declarations must agree, and this is a disclosure rule, not
+    // tidiness.**
+    //
+    // A create body can carry an explicit `productGroup` *and* a
+    // `productGroupData` whose internal tag says something else. Nothing
+    // compared them, and the two are read by different things: the explicit
+    // value becomes the stored `product_group` and picks `schemaVersion`, while
+    // the payload is schema-validated against its own tag. Both halves pass.
+    //
+    // What that reaches is the public view. `publish` filters through
+    // `ProductGroupAccessPolicy::for_schema_version(passport.product_group, …)`
+    // — the **label** — and a policy that resolves is not the fail-closed case,
+    // so the backstop never fires. Every payload field the label's table does
+    // not name falls to `default_disclosure`, which is `Public`. Battery's table
+    // names neither `svhcSubstances` nor `disassemblyInstructions`; textile's
+    // marks both `restricted`. So textile data under a battery label publishes
+    // the REACH Art. 33 substance declarations — and signs them into
+    // `publicJwsSignature`, where a published passport cannot be edited, only
+    // superseded.
+    //
+    // Refused rather than reconciled: either choice silently discards a
+    // declaration the caller made, and this is a create, so there is no existing
+    // record whose meaning a rejection would change.
+    if let (Some(explicit), Some(data)) = (&body.product_group, &body.product_group_data)
+        && explicit != &data.product_group()
+    {
+        return api_error(
+            StatusCode::UNPROCESSABLE_ENTITY,
+            "VALIDATION_ERROR",
+            &format!(
+                "productGroup says `{}` and productGroupData says `{}`. They select different \
+                 disclosure tables, so a passport carrying both would be published under one \
+                 product group's rules while holding another's data. Send one, or make them agree.",
+                explicit.catalog_key(),
+                data.product_group().catalog_key()
+            ),
+        );
+    }
+
     let product_group = body
         .product_group
         .clone()
@@ -869,3 +908,98 @@ mod life_status_at_create {
         }
     }
 }
+
+#[cfg(test)]
+mod the_label_must_match_its_payload {
+    //! A passport's product group is the key that picks the disclosure table its
+    //! public view is filtered and signed under. These pin that it cannot
+    //! disagree with the payload it is filtering.
+    //!
+    //! 🚨 The failure this prevents is a **disclosure** one, not a tidiness one.
+    //! `publish` resolves `ProductGroupAccessPolicy::for_schema_version` from the
+    //! stored `product_group` — the label. A coherent-but-wrong label resolves
+    //! perfectly, so `audience_view`'s fail-closed backstop (which keys on the
+    //! policy failing to resolve) never fires, and every payload field the
+    //! label's table does not name falls to `default_disclosure`, which is
+    //! `Public`. Battery's table names neither `svhcSubstances` nor
+    //! `disassemblyInstructions`; textile's marks both `restricted`.
+    use super::*;
+
+    fn textile_payload() -> serde_json::Value {
+        serde_json::json!({
+            "productGroup": "textile",
+            "gtin": "09506000134352",
+            "fibreComposition": [{ "fibre": "cotton", "pct": 100.0 }],
+            "careInstructions": "wash cold",
+            "countryOfOrigin": "PT",
+            "chemicalComplianceStandard": "oeko-tex-100",
+        })
+    }
+
+    fn parse(v: serde_json::Value) -> CreatePassportRequest {
+        serde_json::from_value(v).expect("a well-formed create body")
+    }
+
+    /// 🚨 A label that contradicts its payload is refused at create.
+    #[test]
+    fn a_product_group_that_contradicts_its_payload_is_refused() {
+        let req = parse(serde_json::json!({
+            "productName": "A unit",
+            "manufacturer": { "name": "M", "address": "A" },
+            "productGroup": "battery",
+            "productGroupData": textile_payload(),
+        }));
+
+        assert!(
+            validate_create_request(&req).is_some(),
+            "battery label over textile data must be refused — it would publish textile's \
+             restricted fields through battery's disclosure table"
+        );
+    }
+
+    /// The two agreeing is the ordinary case and stays lawful.
+    #[test]
+    fn a_label_that_matches_its_payload_is_accepted() {
+        let req = parse(serde_json::json!({
+            "productName": "A unit",
+            "manufacturer": { "name": "M", "address": "A" },
+            "productGroup": "textile",
+            "productGroupData": textile_payload(),
+        }));
+
+        assert!(
+            validate_create_request(&req).is_none(),
+            "a body whose two declarations agree must be accepted"
+        );
+    }
+
+    /// Declaring only the payload stays lawful — the label is derived from it.
+    ///
+    /// The check is about a *contradiction*, not about requiring both. Omitting
+    /// the explicit group is the documented way to let `productGroupData` decide.
+    #[test]
+    fn omitting_the_explicit_group_is_not_a_contradiction() {
+        let req = parse(serde_json::json!({
+            "productName": "A unit",
+            "manufacturer": { "name": "M", "address": "A" },
+            "productGroupData": textile_payload(),
+        }));
+
+        assert!(
+            validate_create_request(&req).is_none(),
+            "with no explicit productGroup there is nothing to contradict"
+        );
+    }
+
+    /// And a label with no payload at all is still fine.
+    #[test]
+    fn a_label_with_no_payload_is_not_a_contradiction() {
+        let req = parse(serde_json::json!({
+            "productName": "A unit",
+            "manufacturer": { "name": "M", "address": "A" },
+            "productGroup": "battery",
+        }));
+
+        assert!(validate_create_request(&req).is_none());
+    }
+}