# originalTransactionId The original transaction identifier of a purchase. ``` string originalTransactionId ``` ## Discussion The App Store generates an original transaction identifier when a customer makes a successful in-app purchase. Most App Store Server API endpoints accept an `originalTransactionId`. There are several ways to obtain this value: from your app after a user makes a successful in-app purchase, from transaction information provided in , or from for apps that use the . To get the original transaction identifier from your app, use the property of the object that represents the in-app purchase. If you’ve enabled , your server receives notifications for in-app purchase events that include the transaction information with the original transaction identifier. For more information, see . If your app uses the , the original transaction identifier is the property in the object. For restored purchases, the original transaction identifier is found in the of the property. If you verify receipts using , the original transaction identifier is the value. Use the value of the original transaction identifier that you get from your app, a notification, or a receipt as the value for [`originalTransactionId`](/documentation/AppStoreServerAPI/originalTransactionId) when you send requests to the App Store Server API. > Tip: > If you maintain a database to manage your subscribers, save the original transaction identifier to uniquely identify auto-renewable subscriptions. --- 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)