---
title: invalidSourceIdentifier
framework: storekittest
role: symbol
role_heading: Type Property
path: storekittest/skadtesterror/invalidsourceidentifier
---

# invalidSourceIdentifier

The postback’s identifier isn’t two, three, or four digits.

## Declaration

```swift
static var invalidSourceIdentifier: SKAdTestError.Code { get }
```

## Discussion

Discussion A valid postback includes two to four digits of the impression’s sourceIdentifier. For more information about the varying length of source identifiers, see Receiving postbacks in multiple conversion windows.

## See Also

### Getting Other Errors

- [invalidVersion](storekittest/skadtesterror/invalidversion.md)
- [invalidImpressionId](storekittest/skadtesterror/invalidimpressionid.md)
- [invalidSourceAppAdamId](storekittest/skadtesterror/invalidsourceappadamid.md)
- [invalidSourceDomain](storekittest/skadtesterror/invalidsourcedomain.md)
- [unknownError](storekittest/skadtesterror/unknownerror.md)