Hi, I am designing a database schema to store App Store transaction data for our backend system, and I have a question regarding the uniqueness of transactionId. According to the documentation (apple.com), transactionId is a unique identifier for a transaction. However, it is not explicitly clear whether this uniqueness is guaranteed across different environments.Could you please clarify the following points? Is transactionId guaranteed to be unique across both the Production and Sandbox environments? (i.e., Is there any possibility that the exact same transactionId is generated in both environments?) For database design, is it safe to use transactionId alone as a Primary Key? Or is it strongly recommended to use a composite key consisting of both environment and transactionId? Any insights or best practices from Apple engineers or the community would be highly appreciated.Thank you.

Hello, I would like to clarify the exact technical behavior of the App Store Server API (V2) and StoreKit under the following two specific scenarios: Case A (Production Account on Sandbox Endpoint): If a user with a production Apple Account attempts to purchase through a build pointing to the Apple Sandbox environment (or Sandbox API), how does the Apple server handle this transaction and its data lifecycle? (Does StoreKit block this at the client-side, or does the API return a specific error code?) Case B (Restoring Cleared Sandbox Data): If a Sandbox tester's purchase history is cleared/deleted on the Apple server, and the app subsequently requests a "Restore Purchase" or queries the App Store Server API using a previously valid transactionID from that account, what specific error code (such as 4040010 TransactionNotFound) or empty response does the Apple server return? I would highly appreciate your confirmation or any technical insights on these behaviors. Thank you!

Hello, I would like to clarify the best practices and timing for our backend server to transition its main connection to the production App Store Server API. Currently, we are considering the following approach: We plan to switch our backend’s primary API endpoint from Sandbox to Production once our app passes the App Store review and its status changes to "Ready for Sale." Could you please confirm if this timing is standard and correct? Additionally, to handle App Store reviews (which run in the Sandbox environment) and TestFlight tests seamlessly without manual configuration changes, we are planning to implement an automatic fallback mechanism: Our backend always requests the Production App Store Server API first. If it returns a "TransactionNotFound" (e.g., 4040010) error, the backend automatically retries the request using the Sandbox API. Is this automatic fallback from Production to Sandbox considered a safe and recommended practice by Apple, especially for App Store reviews and post-release testing? Any advice or insights on backend transition timing and fallback strategies would be highly appreciated. Thank you!

Hi, During the App Review process, a test purchase was made using what appeared to be a production Apple account. When our app server sent this transactionId to the Production App Store Server API, it returned the error code 4040010 (TransactionIdNotFoundError). To handle this gracefully and prevent review rejections, we are considering implementing a dynamic fallback mechanism on our app server. Specifically, when the Production API returns 4040010, the server will automatically retry the request using the Sandbox App Store Server API URL. Could you please clarify the following points regarding this design? Is it expected behavior for an App Review purchase to return 4040010 on the Production API, and can it be successfully verified by routing it to the Sandbox API? Is this dynamic fallback logic (Production API ➔ if 4040010 ➔ Sandbox API) a recommended and officially supported best practice for handling App Review and TestFlight transactions? Any confirmation or advice from Apple engineers or the community would be greatly appreciated.Thank you.

Isn't there a way for developers to make custom adjustments to the transferred revenue, such as changing the minimum payment amount to 100,000 yen? Looking at the site below, I thought that the minimum payment amount determined by Apple for each region and currency is fixed and cannot be customized. Is this correct? https://developer.apple.com/help/app-store-connect/reference/reporting/minimum-payment-threshold

アプリ内課金を実装しようとしていますが、サーバサイドのセキュリティに関してについて質問です。 StoreKit２を使えばアプリとApp Store Connect間のレシート検証は不要だが、 購入情報をサーバーで管理する場合は アプリからサーバーに購入情報を渡す際にレシート検証する必要があると考えるがその認識であっているか教えていただきたいです。

アプリに課金を実装しようと思うのですが、もし不正利用された場合、アプリ側は基本的にApp Storeを通じて対応するよう案内するのが一般的と思いますが、Apple ID不正利用時とクレジットカード不正利用時で、アプリ側が行う標準的な対応プロセスは変わるのか教えていただきたいです。 また下記内容は標準的な対応プロセスとして問題ないでしょうか？
 ■Apple ID不正利用時 → ユーザー自身がAppleサポートに連絡し、パスワード変更・二段階認証の設定・不正購入の返金申請などを行うよう案内する。 ■クレジットカード不正利用時 → まずカード会社への連絡を促すが、アプリ内決済に関してはAppleのカスタマーサポート経由で返金や調査手続きを案内する 不正利用されたユーザーへの対応に備えて、アプリ側が考慮すべきことがあれば教えてください。