diff --git a/mintlify/openapi.yaml b/mintlify/openapi.yaml
index 6a2a8401..1b084bbf 100644
--- a/mintlify/openapi.yaml
+++ b/mintlify/openapi.yaml
@@ -9073,7 +9073,15 @@ components:
         - customerType
       properties:
         customerType:
-          $ref: '#/components/schemas/CustomerType'
+          allOf:
+            - $ref: '#/components/schemas/CustomerType'
+          description: |
+            Must equal the existing customer's `customerType`. This field is required
+            on PATCH because it discriminates the request body shape (INDIVIDUAL vs
+            BUSINESS); it is not the way to change customer type. Requests that
+            submit a different `customerType` than the existing record will be
+            rejected with `INVALID_INPUT`. To change the legal classification of a
+            customer, create a new customer and migrate its accounts.
         currencies:
           type: array
           items:
diff --git a/openapi.yaml b/openapi.yaml
index 6a2a8401..1b084bbf 100644
--- a/openapi.yaml
+++ b/openapi.yaml
@@ -9073,7 +9073,15 @@ components:
         - customerType
       properties:
         customerType:
-          $ref: '#/components/schemas/CustomerType'
+          allOf:
+            - $ref: '#/components/schemas/CustomerType'
+          description: |
+            Must equal the existing customer's `customerType`. This field is required
+            on PATCH because it discriminates the request body shape (INDIVIDUAL vs
+            BUSINESS); it is not the way to change customer type. Requests that
+            submit a different `customerType` than the existing record will be
+            rejected with `INVALID_INPUT`. To change the legal classification of a
+            customer, create a new customer and migrate its accounts.
         currencies:
           type: array
           items:
diff --git a/openapi/components/schemas/customers/CustomerUpdateRequest.yaml b/openapi/components/schemas/customers/CustomerUpdateRequest.yaml
index 15cccec5..a6406296 100644
--- a/openapi/components/schemas/customers/CustomerUpdateRequest.yaml
+++ b/openapi/components/schemas/customers/CustomerUpdateRequest.yaml
@@ -9,7 +9,15 @@ required:
   - customerType
 properties:
   customerType:
-    $ref: ./CustomerType.yaml
+    allOf:
+      - $ref: ./CustomerType.yaml
+    description: |
+      Must equal the existing customer's `customerType`. This field is required
+      on PATCH because it discriminates the request body shape (INDIVIDUAL vs
+      BUSINESS); it is not the way to change customer type. Requests that
+      submit a different `customerType` than the existing record will be
+      rejected with `INVALID_INPUT`. To change the legal classification of a
+      customer, create a new customer and migrate its accounts.
   currencies:
     type: array
     items: