---
title: SMSService.Error.unknown
framework: TelephonyMessagingKit
role: symbol
role_heading: Case
platforms: [iOS 26.0+]
path: telephonymessagingkit/smsservice/error/unknown
---

# SMSService.Error.unknown

An unknown problem caused the error.

## Declaration

```swift
case unknown
```

## See Also

### Identifying errors

- [SMSService.Error.notSupported](telephonymessagingkit/smsservice/error/notsupported.md)
- [SMSService.Error.permanentFailure](telephonymessagingkit/smsservice/error/permanentfailure.md)
- [SMSService.Error.temporaryFailure](telephonymessagingkit/smsservice/error/temporaryfailure.md)