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

# Update SIP Trunk

> Update an existing SIP trunk configuration in Famulor via API. Change credentials, routing rules and assigned phone numbers for your AI voice telephony.

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](/en/api-reference/sip-trunks/get))
</ResponseField>

<ResponseExample>
  ```json 200 Updated credentials theme={null} 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} 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} theme={null}
  {
    "error": "SIP trunk not found."
  }
  ```

  ```json 422 Validation Error theme={null} 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} 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` and `country_code` are stored locally and do not trigger re-provisioning.