> ## Documentation Index
> Fetch the complete documentation index at: https://docs.autocalls.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Update SIP trunk

> Update an existing SIP trunk configuration

This endpoint updates an existing SIP trunk. Only include the fields you want to change — partial updates are supported. Changing credentials, address, or proxy settings automatically re-provisions the affected voice infrastructure trunks.

### Path Parameters

<ParamField path="id" type="integer" required>
  The unique identifier of the SIP trunk to update
</ParamField>

### Body Parameters

All fields are optional. Only send the fields you want to update.

<ParamField body="phone_number" type="string" optional>
  The SIP extension or phone number (1-15 characters)
</ParamField>

<ParamField body="nickname" type="string" optional>
  A short, human-friendly label for the trunk. Maximum 50 characters. Send `null` to clear it.
</ParamField>

<ParamField body="sip_username" type="string" optional>
  Username for SIP authentication (3-128 characters)
</ParamField>

<ParamField body="sip_password" type="string" optional>
  Password for SIP authentication (minimum 3 characters)
</ParamField>

<ParamField body="sip_address" type="string" optional>
  The SIP server address without port
</ParamField>

<ParamField body="sip_calling_format" type="string" optional>
  The outbound calling number format: `+e164`, `e164`, or `national`
</ParamField>

<ParamField body="inbound_authorization_type" type="string" optional>
  How inbound calls are authenticated: `auth` or `ip`. When switching to `ip`, you must also provide `allowed_inbound_ips`. When switching to `auth`, any existing IP whitelist is cleared.
</ParamField>

<ParamField body="allowed_inbound_ips" type="array" optional>
  Array of IP addresses allowed for inbound calls. **Required** when `inbound_authorization_type` is set to `ip`.
</ParamField>

<ParamField body="country_code" type="string" optional>
  ISO 3166-2 country code
</ParamField>

<ParamField body="outbound_proxy" type="boolean" optional>
  Route outbound calls through a fixed IP address
</ParamField>

### Response

<ResponseField name="message" type="string">
  Success message
</ResponseField>

<ResponseField name="data" type="object">
  The updated SIP trunk object (same fields as [Get SIP trunk](/api-reference/sip-trunks/get-sip-trunk))
</ResponseField>

<ResponseExample>
  ```json 200 Updated credentials theme={null}
  {
    "message": "SIP trunk updated successfully.",
    "data": {
      "id": 42,
      "phone_number": "1000",
      "nickname": "Provider X — Main",
      "sip_username": "new_username",
      "sip_address": "sip.provider.com",
      "sip_calling_format": "+e164",
      "inbound_authorization_type": "auth",
      "allowed_inbound_ips": null,
      "outbound_proxy": false,
      "country_code": "US",
      "inbound_trunk_id": "ST_newtrunkid1",
      "outbound_trunk_id": "ST_newtrunkid2",
      "created_at": "2026-03-31T10:00:00.000000Z",
      "updated_at": "2026-03-31T12:00:00.000000Z"
    }
  }
  ```

  ```json 200 Switched to IP auth theme={null}
  {
    "message": "SIP trunk updated successfully.",
    "data": {
      "id": 42,
      "phone_number": "1000",
      "nickname": "Provider X — Main",
      "sip_username": "myuser",
      "sip_address": "sip.provider.com",
      "sip_calling_format": "+e164",
      "inbound_authorization_type": "ip",
      "allowed_inbound_ips": ["203.0.113.10"],
      "outbound_proxy": false,
      "country_code": "US",
      "inbound_trunk_id": "ST_newtrunkid1",
      "outbound_trunk_id": "ST_yyyyyyyyyyyy",
      "created_at": "2026-03-31T10:00:00.000000Z",
      "updated_at": "2026-03-31T12:00:00.000000Z"
    }
  }
  ```

  ```json 404 Not Found theme={null}
  {
    "error": "SIP trunk not found."
  }
  ```

  ```json 422 Validation Error theme={null}
  {
    "message": "The given data was invalid.",
    "errors": {
      "allowed_inbound_ips": ["At least one allowed IP address is required when authorization type is \"ip\"."]
    }
  }
  ```

  ```json 500 Provisioning Error theme={null}
  {
    "error": "Failed to update SIP trunk. Please try again or contact support."
  }
  ```
</ResponseExample>

### Re-provisioning behavior

The following field changes trigger automatic re-provisioning of voice infrastructure trunks:

| Field changed                | Inbound trunk | Outbound trunk |
| ---------------------------- | :-----------: | :------------: |
| `sip_username`               |   Re-created  |   Re-created   |
| `sip_password`               |   Re-created  |   Re-created   |
| `sip_address`                |       —       |   Re-created   |
| `phone_number`               |   Re-created  |   Re-created   |
| `inbound_authorization_type` |   Re-created  |        —       |
| `allowed_inbound_ips`        |   Re-created  |        —       |
| `outbound_proxy`             |       —       |   Re-created   |

Fields like `sip_calling_format`, `country_code` are stored locally and do not trigger re-provisioning.