---
title: transactionIdentifier
framework: storekit
role: symbol
role_heading: Instance Property
path: storekit/skpaymenttransaction/transactionidentifier
---

# transactionIdentifier

A string that uniquely identifies a successful payment transaction.

## Declaration

```swift
var transactionIdentifier: String? { get }
```

## Discussion

Discussion The contents of this property are undefined except when transactionState is set to SKPaymentTransactionState.purchased or SKPaymentTransactionState.restored. The transactionIdentifier is a string that uniquely identifies an interaction between the user’s device and the App Store, such as a purchase or restore. This value has the same format as the transaction’s transaction_id in the receipt; however, the values may not be the same.

## See Also

### Getting Transaction Information

- [payment](storekit/skpaymenttransaction/payment.md)
- [transactionDate](storekit/skpaymenttransaction/transactiondate.md)
- [original](storekit/skpaymenttransaction/original.md)
- [error](storekit/skpaymenttransaction/error.md)
- [transactionReceipt](storekit/skpaymenttransaction/transactionreceipt.md)