diff --git a/src/openapi/fiko/fiko-crud.yaml b/src/openapi/fiko/fiko-crud.yaml
index d3a48ac..9425e09 100644
--- a/src/openapi/fiko/fiko-crud.yaml
+++ b/src/openapi/fiko/fiko-crud.yaml
@@ -108,13 +108,19 @@ paths:
           schema:
             type: string
             example: FIKO-123456
-          description: The aggregation reference of the transaction.
+          description: The aggregation reference of the transaction. %00 is searching for NULL-values.
         - in: query
           name: accountingSystemReference
           schema:
             type: string
             example: U4F-123456
-          description: The accounting system reference of the transaction.
+          description: The accounting system reference of the transaction. %00 is searching for NULL-values.
+        - in: query
+          name: highestProcessingFailureStatus
+          schema:
+            type: string
+            example: open
+          description: Find the highest processing failure status of the transaction. %00 is searching for NULL-values.
       responses:
         "200":
           description: OK
@@ -756,12 +762,6 @@ paths:
             type: string
             example: 900
           description: The department.
-        - in: query
-          name: costCenter
-          schema:
-            type: string
-            example: 84955
-          description: The cost center.
         - in: query
           name: costType
           schema:
@@ -818,6 +818,12 @@ paths:
             format: uuid
             example: 08d96f94-f468-467e-9068-c86c34f43097
           description: Find product metadata that is linked to this source metadata.
+        - in: query
+          name: costCenter
+          schema:
+            type: string
+            example: 84955
+          description: Find product metadata that is linked to this cost center.
       responses:
         "200":
           description: OK
@@ -833,7 +839,6 @@ paths:
                         "productMetadataId": "39a87c2a-9011-4dfd-b35e-1245a98c2e61",
                         "productCode": "4031",
                         "department": "900",
-                        "costCenter": "84955",
                         "costType": "619031",
                         "description": "O4031_Reisproduct HTM 1 dag Anoniem",
                         "documentCode": "VERK_FACTUUR",
@@ -865,6 +870,7 @@ paths:
                                   "validFrom": "2024-01-01T00:00:00.000",
                                   "validUntil": null,
                                 },
+                              "costCenter": "84955",
                               "validFrom": "2024-03-22T09:00:00",
                               "validUntil": null,
                             },
@@ -927,6 +933,7 @@ paths:
                       "contraAccountMetadataId": "e0af8c8f-d421-4567-a14e-48e2a1bb86fb",
                       "concessionId": 1,
                       "sourceMetadataId": "08d96f94-f468-467e-9068-c86c34f43097",
+                      "costCenter": "84955",
                       "validFrom": "2024-03-22T09:00:00",
                       "validUntil": null,
                     },
@@ -934,6 +941,7 @@ paths:
                       "contraAccountMetadataId": "02e458ce-f77a-4262-8b38-490e54f52856",
                       "concessionId": 2,
                       "sourceMetadataId": "08d96f94-f468-467e-9068-c86c34f43097",
+                      "costCenter": "84955",
                       "validFrom": "2024-03-22T09:00:00",
                       "validUntil": null,
                     },
@@ -973,7 +981,6 @@ paths:
               {
                 "productCode": "4031",
                 "department": "900",
-                "costCenter": "84955",
                 "costType": "619031",
                 "description": "O4031_Reisproduct HTM 1 dag Anoniem",
                 "documentCode": "VERK_FACTUUR",
@@ -990,6 +997,47 @@ paths:
                 $ref: "#/components/schemas/unavailable"
               example:
                 { "productMetadataId": "39a87c2a-9011-4dfd-b35e-1245a98c2e61" }
+  /productmetadata/{productMetadataId}/productcontraaccounts:
+    parameters:
+      - in: path
+        name: productMetadataId
+        schema:
+          type: string
+          format: uuid
+          example: 37a8095b-19db-498f-9349-5f37d21c5bdf
+        required: true
+        description: The id of the product metadata.
+    post:
+      summary: Add product contra account.
+      description: Add product contra account.
+      tags:
+        - Metadata v2
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/unavailable"
+            example:
+              {
+                "contraAccountMetadataId": "e0af8c8f-d421-4567-a14e-48e2a1bb86fb",
+                "concessionId": 1,
+                "sourceMetadataId": "08d96f94-f468-467e-9068-c86c34f43097",
+                "costCenter": "84955",
+                "validFrom": "2024-03-22T09:00:00",
+                "validUntil": null,
+              }
+      responses:
+        "201":
+          description: Created
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/unavailable"
+              example:
+                {
+                  "productContraAccountId": "39a87c2a-9011-4dfd-b35e-1245a98c2e61",
+                }
   /productcontraaccounts/{productContraAccountId}:
     parameters:
       - in: path
@@ -1016,6 +1064,7 @@ paths:
                 "contraAccountMetadataId": "e0af8c8f-d421-4567-a14e-48e2a1bb86fb",
                 "concessionId": 1,
                 "sourceMetadataId": "08d96f94-f468-467e-9068-c86c34f43097",
+                "costCenter": "84955",
                 "validFrom": "2024-03-22T09:00:00",
                 "validUntil": null,
               }