# E21051 — VoiceTrunkOutboundNotEnabled

This SIP trunk does not have outbound calling enabled.

- **HTTP status**: `412`
- **Type**: `precondition_error`
- **Name**: `VoiceTrunkOutboundNotEnabled`

## What to do

On an existing trunk, enable outbound calling and set its connection and authentication settings; the same update can do both at once. On a create, send outbound_enabled true alongside the settings, since there is no trunk to update yet.

Operations that resolve this:

- [Update a SIP trunk](/docs/api/reference/update-voice-trunk)
- [Create a SIP trunk](/docs/api/reference/create-voice-trunk)

## Related

- [E21xxx — Voice & SIP trunking](/docs/api/errors/E21xxx): every code in this range
- [Errors](/docs/api/errors): the full wire contract, status mapping, and error catalog
- [Error handling](/docs/guides/errors): branching on `type` and `code`, validation details, and `vendor_code`

## Related resources

- [Should I use a Bird SDK or call the API directly?](/explained/platform/should-i-use-an-sdk-or-call-the-api-directly) (answer)
- [Build your first integration](/learn/paths/integration) (course)
- [Send your first email](/docs/get-started/send-your-first-email) (docs)

[Get an implementation brief](/learn/workspace?topic=api-basics)