---
title: "Create SIP Trunk"
method: POST
path: "/user/phone-numbers/sip-trunks"
tags: ["SIP Trunks"]
---

# Create SIP Trunk

`POST /user/phone-numbers/sip-trunks`

## Request

- Base URL: `https://app.famulor.de/api`
- URL: `https://app.famulor.de/api/user/phone-numbers/sip-trunks`
- Auth: HTTP bearer

Create a new SIP trunk with credentials, address, and proxy settings

[Docs](https://docs.famulor.io/api-v1/sip-trunks/create)

## Request body

- object
  - `sip_trunk_type` string, required: The type of SIP trunk: `extension` for a SIP extension, or `number` for a phone number (DID). This determines the expected format of the `phone_number` field.
  - `phone_number` string, required: The SIP extension (1-15 characters, e.g. `1000`) when `sip_trunk_type` is `extension`, or a phone number in E.164 format (e.g. `+14155551234`) when `sip_trunk_type` is `number`.
  - `nickname` string: A short, human-friendly label for the trunk (e.g. "Provider X — Main"). Maximum 50 characters.
  - `sip_username` string, required: Username for SIP authentication (3-128 characters)
  - `sip_password` string, required: Password for SIP authentication (minimum 3 characters)
  - `sip_address` string, required: The SIP server address without port (e.g. `sip.provider.com`)
  - `sip_calling_format` string, required: The outbound calling number format: * `+e164` - International with `+` prefix (e.g. `+12025550123`) * `e164` - International without `+` prefix (e.g. `12025550123`) * `national` - National format without country code (e.g. `0741926265`)
  - `inbound_authorization_type` string, required: How inbound calls are authenticated: * `auth` - Uses the same SIP username and password configured for outbound * `ip` - Whitelists specific IP addresses (requires `allowed_inbound_ips`)
  - `allowed_inbound_ips` unknown[]: Array of IP addresses allowed to send inbound calls. **Required** when `inbound_authorization_type` is `ip`. Must contain at least one valid IP address.
    - unknown
  - `country_code` string, required: ISO 3166-2 country code where the SIP trunk is located (e.g. `US`, `GB`, `DE`). When `sip_trunk_type` is `number`, the country is auto-detected from the phone number if possible.
  - `outbound_proxy` boolean: Route outbound calls through a fixed IP address. Default: `false`. Only enable this if your SIP provider requires IP-based authentication for outbound traffic.

## Response `201`

Created

- object
  - `message` string: Success message
  - `data` object: The created SIP trunk object (same fields as [Get SIP trunk](/en/api-reference/sip-trunks/get))

## Other responses

- `401`: Fehlender oder ungültiger API-Key.
- `409`: Duplicate
- `422`: Validation Error
- `500`: Provisioning Error

---

[API](https://skmtc.dev/famulor/apis/famulor-api.md) · [All operations](https://skmtc.dev/famulor/apis/famulor-api/llms.txt) · [OpenAPI document](https://skmtc.dev/famulor/apis/famulor-api/revisions/3b938c370721?raw)