非续订订阅沙箱模式重复购买异常及多用户设备适配问题咨询

Hey there, let’s tackle your non-renewing subscription questions one by one—since you’re in sandbox testing, some of these behaviors are specific to Apple’s test environment, so let’s break it down clearly!

Non-renewing subscriptions are designed to be purchasable multiple times, so that sandbox prompt ("This In-App purchase has already been bought...") is just Apple’s test environment protecting you from accidental duplicate purchases. Here’s how to let users re-subscribe:

• Separate Purchase vs. Restore Flows: Don’t rely on automatic restoration for repeat purchases. Build two distinct actions in your UI: one for "Buy New Subscription" and another for "Restore Purchases". When a user selects "Buy New", directly initiate a new purchase request instead of triggering restoration.
• Reset Sandbox Test Accounts: To test repeat purchases with the same test user, head to App Store Connect → Users and Access → Sandbox Testers, find your test account, and click "Reset Purchase History". This clears their sandbox purchase records, letting you buy the same product again.
• Code Example (Swift):

  func startNewPurchase(for product: SKProduct) {
      let payment = SKPayment(product: product)
      SKPaymentQueue.default().add(payment)
  }
  
  func restoreExistingPurchases() {
      SKPaymentQueue.default().restoreCompletedTransactions()
  }
  

  In production, users will be able to buy the same non-renewing product as long as it’s configured to allow repeat purchases (which is the default)—the sandbox prompt won’t appear here.

The key here is to tie subscription state to user accounts, not the device. Non-renewing subscriptions don’t get managed by Apple’s subscription system, so you’ll need to handle this entirely on your backend:

• Sync Subscription State on Login: When a new user logs in, never trust local cached subscription data. Fetch the user’s subscription history directly from your backend—this ensures you’re loading the correct data for the logged-in user, not the previous one on the device.
• Clear Local Cache on User Switch: When a user logs out, wipe any local storage related to their subscriptions (like cached purchase receipts or active subscription status) to prevent cross-user data leaks.
• Bind Restore Actions to the Current User: When a user taps "Restore Purchases", send the restored receipt to your backend. Your backend should validate the receipt and link the subscription to the currently logged-in user’s account—not the device. This way, restoring only pulls in the current user’s past purchases.
• Test with Multiple Sandbox Accounts: Use different sandbox tester accounts to log in and out of your app, verifying that each user’s subscriptions are isolated and don’t overlap.

A quick reminder: Unlike auto-renewable subscriptions, Apple doesn’t track non-renewing subscription status for you. You’ll need to store all purchase details (receipts, expiration dates, user associations) in your backend to make multi-user scenarios work reliably.

内容的提问来源于stack exchange，提问作者Krishna Maru