diff --git a/versions/2.x/models/BookingService.json b/versions/2.x/models/BookingService.json
index e664efc1..d91f1f58 100644
--- a/versions/2.x/models/BookingService.json
+++ b/versions/2.x/models/BookingService.json
@@ -35,7 +35,8 @@
     "name",
     "url",
     "termsOfService",
-    "softwareVersion"
+    "softwareVersion",
+    "hasCredential"
   ],
   "notInSpec": [],
   "fields": {
@@ -75,6 +76,14 @@
       "description": [
         "The version of the application, useful for on-premise installations. Note this property is in EARLY RELEASE AND IS SUBJECT TO CHANGE, as the [Dataset API Discovery specification](https://openactive.io/dataset-api-discovery/EditorsDraft/) evolves."
       ]
+    },
+    "hasCredential": {
+      "fieldName": "hasCredential",
+      "sameAs": "https://pending.schema.org/hasCredential",
+      "requiredType": "https://schema.org/URL",
+      "description": [
+        "A human and machine-readable certification file that asserts the service's conformance to established standards. The value of this property should be a URL that resolves to a valid and up-to-date OpenActive Test Suite Conformance Certificate for this implementation. Note this property is in EARLY RELEASE AND IS SUBJECT TO CHANGE, as the [Dataset API Discovery specification](https://openactive.io/dataset-api-discovery/EditorsDraft/) evolves."
+      ]
     }
   }
 }
\ No newline at end of file