FlutterInappPurchase.purchaseUpdated.listen(..) is triggered earlier than the transactionDate

[jyjeon-715]

❓ Your Question

We are currently migrating from StoreKit 1 to StoreKit 2.
The issue occurs in the current production App Store application.

We are using an older version of Flutter and in-app purchase libraries, and upgrading them is not an option at the moment.

Why is FlutterInappPurchase.purchaseUpdated.listen(..) triggered earlier than the transactionDate?

This is happening in the iOS sandbox environment.
The first subscription is a free trial (3 minutes), followed by recurring charges every 5 minutes.

💻 Current Code

Future<void> init(AppState state) async {
   ...
    FlutterInappPurchase.purchaseUpdated.listen((productItem) {
      debugPrint('=============== purchase-updated: $productItem');


      final nowMs = DateTime.now().millisecondsSinceEpoch;
      final dateTime = DateTime.fromMillisecondsSinceEpoch(nowMs);
      debugPrint('>> dateTime = $nowMs ------> ($dateTime)');
   });
   ...
}

Logs:
1. First payment
=============== purchase-updated: productId: .., transactionId: .., transactionDate: **2025-12-12T15:16:13.000**, transactionReceipt: ...
>> dateTime = 1765520177927 ------> (**2025-12-12 15:16:17.927**)

2. updated
 Purchase Successful !! 
=============== purchase-updated: productId: .., transactionId: .., transactionDate: **2025-12-12T15:19:13.000**, transactionReceipt: ...
>> dateTime = 1765520331297 ------> (**2025-12-12 15:18:51.297**)

2. updated
 Purchase Successful !! 
=============== purchase-updated: productId: .., transactionId: .., transactionDate: **2025-12-12T15:24:13.000**, transactionReceipt: ...
>> dateTime = 1765520637362 ------> (**2025-12-12 15:23:57.362**)

📱 Environment

Flutter doctor:

    • Flutter version 3.16.3
    • Dart version 3.2.3
    • DevTools version 2.28.4

Package version:

• flutter_inapp_purchase: ^5.4.2

Platform:

• [✔️] iOS
• Android

[hyochan]

This timing difference is expected behavior from Apple's StoreKit 2, not a bug in flutter_inapp_purchase.

Why This Happens

Concept	Description
transactionDate	When Apple scheduled the renewal (from Transaction.purchaseDate)
purchaseUpdated event	When your device received the notification

For subscription renewals in sandbox:

1. Apple creates the transaction with a future transactionDate (e.g., 15:19:13)
2. But delivers the notification to your device slightly earlier (e.g., 15:18:51)
3. Result: Event received time < transactionDate

This is Apple's intended behavior - they pre-notify devices about upcoming renewals.

Recommendation

Don't rely on transactionDate for timing logic. Instead, use server-side validation to get accurate subscription status:

final result = await iap.verifyPurchaseWithProvider(
  VerifyPurchaseWithProviderProps(
    provider: PurchaseVerificationProvider.iapkit,
    iapkit: RequestVerifyPurchaseWithIapkitProps(
      apiKey: 'your-api-key',
      apple: RequestVerifyPurchaseWithIapkitAppleProps(
        jws: purchase.purchaseToken ?? '',
      ),
    ),
  ),
);

// Use server response for subscription state
if (result.iapkit?.isValid == true && result.iapkit?.state == 'entitled') {
  // User has valid subscription
}

Server-side validation gives you the accurate subscription state regardless of client-side event timing.

Summary

• This is not a bug - it's how Apple's StoreKit works
• transactionDate represents "when the transaction becomes valid", not "when you received it"
• For reliable subscription status, use server-side receipt validation