# Outbound Trunks

Use the Outbound Trunks resource to create, retrieve, update, and delete SIP trunks used
for outbound calling through DIDWW.

An Outbound Trunk defines how outbound calls are authenticated and controlled. Its
configuration can specify allowed SIP and RTP addresses, CLI policies, destination-prefix
rules, simultaneous-call and 24-hour spending limits, media settings, status, callbacks,
and DIDs allowed for regular or emergency calling.

Outbound Trunks support `credentials_and_ip`, `ip_only`, and `twilio` authentication
when retrieved. New or updated trunks can use `credentials_and_ip` or `twilio`;
`ip_only` cannot be selected through `POST` or `PATCH`.

Note

The Outbound feature is not enabled by default. In version `2026-04-16`, Outbound
Trunks can be created or updated and their credentials can be regenerated through the
API even when the feature is not enabled. For more information, contact DIDWW Sales.

## Endpoints

| Action | Method | Endpoint |
| --- | --- | --- |
| Retrieve all Outbound Trunks | `GET` | `/v3/voice_out_trunks` |
| Retrieve Outbound Trunk | `GET` | `/v3/voice_out_trunks/{id}` |
| Create Outbound Trunk | `POST` | `/v3/voice_out_trunks` |
| Update Outbound Trunk | `PATCH` | `/v3/voice_out_trunks/{id}` |
| Delete Outbound Trunk | `DELETE` | `/v3/voice_out_trunks/{id}` |
| Regenerate Outbound Trunk credentials | `POST` | `/v3/voice_out_trunk_regenerate_credentials` |

## Retrieve all Outbound Trunks

Retrieves all Outbound Trunks configured for the account.

Use this endpoint to filter trunks by name, external reference ID, authentication type,
CLI policy, status, threshold state, destination policy, media encryption, or Emergency
Calling configuration. Related regular and emergency DIDs can be included in the response.

See [Retrieve All Outbound Trunks](get-voice-out-trunks.html).

```
GET /v3/voice_out_trunks
```

## Retrieve Outbound Trunk

Retrieves a specific Outbound Trunk by its unique ID.

Use this endpoint to inspect the trunk's authentication, call policies, limits, media
configuration, status, and related DIDs.

See [Retrieve Outbound Trunk](get-voice-out-trunk.html).

```
GET /v3/voice_out_trunks/{id}
```

## Create Outbound Trunk

Creates an Outbound Trunk using `credentials_and_ip` or `twilio` authentication.

Use this endpoint to configure authentication, allowed network addresses, CLI handling,
destination rules, limits, media behavior, callbacks, and DIDs allowed for regular or
emergency calling. The `ip_only` authentication type cannot be used when creating a
trunk.

See [Create Outbound Trunk](create-voice-out-trunk.html).

```
POST /v3/voice_out_trunks
```

## Update Outbound Trunk

Updates a specific Outbound Trunk.

Use this endpoint to change the trunk's configuration, authentication type, call policies,
limits, status, callbacks, or related DIDs. When the authentication type is changed, the
previous authentication attributes are cleared. The authentication type cannot be changed
to `ip_only`.

See [Update Outbound Trunk](update-voice-out-trunk.html).

```
PATCH /v3/voice_out_trunks/{id}
```

## Delete Outbound Trunk

Permanently deletes a specific Outbound Trunk. A deleted trunk cannot be retrieved.

See [Delete Outbound Trunk](delete-voice-out-trunk.html).

```
DELETE /v3/voice_out_trunks/{id}
```

## Regenerate Outbound Trunk credentials

Regenerates the username and password for an Outbound Trunk that uses
`credentials_and_ip` authentication.

This endpoint does not apply to trunks that use `ip_only` or `twilio` authentication.

See [Regenerate Outbound Trunk Credentials](voice-out-trunk-regenerate-credentials.html).

```
POST /v3/voice_out_trunk_regenerate_credentials
```

## Data reference

See [Outbound Trunk Object](voice-out-trunk-object.html) for the complete trunk attributes,
authentication objects, and DID relationships.

## Common Outbound Trunk use cases

| Use case | Description |
| --- | --- |
| Configure SIP authentication | Authenticate calls using SIP credentials with allowed IP addresses or a Twilio Account SID. |
| Restrict originating addresses | Define the SIP and RTP IP addresses allowed to send signaling and media traffic. |
| Control outbound CLI | Assign eligible DIDs and define how calls are handled when the presented CLI does not match the allowed DID list. |
| Control called destinations | Allow or reject destinations according to the default action and configured prefix exceptions. |
| Manage trunk availability | Set the trunk status to `active` or `blocked`. |
| Apply usage limits | Configure a simultaneous-call limit and a 24-hour threshold amount. |
| Configure media handling | Set allowed RTP addresses, media encryption, symmetric RTP, RTP ping, and timeout behavior. |
| Configure Emergency Calling | Allow all eligible DIDs or select specific emergency-enabled DIDs for Emergency Calling through the trunk. |
| Regenerate credentials | Replace the username and password for a `credentials_and_ip` trunk. |

## Related resources

Use Outbound Trunks together with DIDs and Emergency Calling resources to configure
outgoing call origination.

| Resource | Description |
| --- | --- |
| [DIDs](../did/index.html) | Eligible DID phone numbers that can be used as CLI on an Outbound Trunk. |
| [Emergency Calling Services](../../emergency-resources/emergency-calling-services/index.html) | Emergency Calling services associated with eligible DIDs. |
| [Inbound Trunks](../voice-in-trunks/index.html) | Routing destinations used for incoming rather than outgoing calls. |

On this page