---
title: kCFErrorUnderlyingErrorKey
framework: corefoundation
role: symbol
role_heading: Global Variable
path: corefoundation/kcferrorunderlyingerrorkey
---

# kCFErrorUnderlyingErrorKey

Key to identify the underlying error in the userInfo dictionary.

## Declaration

```swift
let kCFErrorUnderlyingErrorKey: CFString!
```

## See Also

### Constants

- [kCFErrorLocalizedDescriptionKey](corefoundation/kcferrorlocalizeddescriptionkey.md)
- [kCFErrorLocalizedFailureReasonKey](corefoundation/kcferrorlocalizedfailurereasonkey.md)
- [kCFErrorLocalizedRecoverySuggestionKey](corefoundation/kcferrorlocalizedrecoverysuggestionkey.md)
- [kCFErrorDescriptionKey](corefoundation/kcferrordescriptionkey.md)
- [kCFErrorURLKey](corefoundation/kcferrorurlkey.md)
- [kCFErrorFilePathKey](corefoundation/kcferrorfilepathkey.md)