# requestIdentifier A string that contains a unique identifier you provide to track each subscription-renewal-date extension request. ``` string requestIdentifier ``` ## Discussion You provide a `requestIdentifier` in the request body when you call the [`Extend Subscription Renewal Dates for All Active Subscribers`](/documentation/AppStoreServerAPI/Extend-Subscription-Renewal-Dates-for-All-Active-Subscribers) and [`Extend a Subscription Renewal Date`](/documentation/AppStoreServerAPI/Extend-a-Subscription-Renewal-Date) endpoints. The API returns the same request identifier in its response, so you can match your request with the related response. The also include this request identifier in notifications related to the [`Extend Subscription Renewal Dates for All Active Subscribers`](/documentation/AppStoreServerAPI/Extend-Subscription-Renewal-Dates-for-All-Active-Subscribers) endpoint. For more information, see the `RENEWAL_EXTENSION` . To resend the same request due to a timeout or other error, use the same request identifier. Otherwise, create a unique request identifer for each different subscription-renewal-date extension request. > Important: > Provide a `UUID` value for the ``doc://com.apple.appstoreserverapi/documentation/AppStoreServerAPI/requestIdentifier`` when calling the ``doc://com.apple.appstoreserverapi/documentation/AppStoreServerAPI/Extend-Subscription-Renewal-Dates-for-All-Active-Subscribers`` endpoint. The maximum string length is 128 characters. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)