diff --git a/specification/responses/4xx/message_batches/422_DuplicateBatchRequest.yaml b/specification/responses/4xx/message_batches/422_DuplicateBatchRequest.yaml
index f9f96e905..ba177fb08 100644
--- a/specification/responses/4xx/message_batches/422_DuplicateBatchRequest.yaml
+++ b/specification/responses/4xx/message_batches/422_DuplicateBatchRequest.yaml
@@ -1,5 +1,5 @@
 description: |+
-  Request already received and it will be ignored. Note that NHS Notify retains details of your original request for up to 16 months. Duplicate submissions received after this period will still be accepted.
+  Request already received and it will be ignored. Note that NHS Notify retains details of your original request for up to 9 months. Duplicate submissions received after this period will still be accepted.
 
   ### Sandbox
 
diff --git a/specification/responses/4xx/messages/422_DuplicateMessageRequest.yaml b/specification/responses/4xx/messages/422_DuplicateMessageRequest.yaml
index 33d992105..be6af8d24 100644
--- a/specification/responses/4xx/messages/422_DuplicateMessageRequest.yaml
+++ b/specification/responses/4xx/messages/422_DuplicateMessageRequest.yaml
@@ -1,5 +1,5 @@
 description: |+
-  Request already received and it will be ignored. Note that NHS Notify retains details of your original request for up to 16 months. Duplicate submissions received after this period will still be accepted.
+  Request already received and it will be ignored. Note that NHS Notify retains details of your original request for up to 9 months. Duplicate submissions received after this period will still be accepted.
   ### Sandbox
 
   It is possible to trigger this on the sandbox by using the `Prefer` header with a value of `code=422_message`.