---
title: transactionIdentifier
framework: storekittest
role: symbol
role_heading: Instance Property
path: storekittest/skadtestpostback/transactionidentifier
---

# transactionIdentifier

A unique transaction identifier that the system generates.

## Declaration

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

## Discussion

Discussion The system generates this value when you call setPostbacks(_:). This value is an empty string otherwise. Use this value to match the test postback with the response you receive from flushPostbacks(responses:).

## See Also

### Getting general information

- [version](storekittest/skadtestpostback/version.md)
- [postbackSequenceIndex](storekittest/skadtestpostback/postbacksequenceindex.md)
- [isRegistered](storekittest/skadtestpostback/isregistered.md)
- [isRedownload](storekittest/skadtestpostback/isredownload.md)