---
title: "Register sender for project"
method: POST
path: "/v1/projects/{projectId}/whatsapp/senders/{senderId}/register"
tags: ["WhatsApp Senders"]
---

# Register sender for project

`POST /v1/projects/{projectId}/whatsapp/senders/{senderId}/register`

## Request

- Base URL: `https://provisioning.api.sinch.com`
- URL: `https://provisioning.api.sinch.com/v1/projects/{projectId}/whatsapp/senders/{senderId}/register`
- Auth: HTTP basic and HTTP bearer and OAuth 2
  - Client credentials
  - Token URL: `https://auth.sinch.com/oauth2/token`

Triggers sender registration with the requested method. An OTP code will be sent over the requested method that will need to be used in the Verify sender endpoint.

## Path parameters

- `projectId` string, required
- `senderId` string, required

## Request body

- WhatsappSenderInputRegisterDto
  - `method` 'SMS' | 'VOICE', required: Registration Method of the sender.

## Response `200`

- WhatsappSenderRegisterDto
  - `id` string, required: The unique ID of the sender.
  - `method` 'SMS' | 'VOICE' | 'UNRECOGNIZED', required: Registration Method of the sender.
  - `accepted` string, required: The UTC Date Time in ISO 8601 for when the sender was accepted.
  - `verificationCodeSent` boolean, required: Whether the verification code has been sent.

## Other responses

- `400`: BadRequest
- `401`: Unauthorized
- `404`: NotFound
- `409`: Conflict
- `429`: TooManyRequests
- `500`: InternalServerError

## Changes

> 17 revisions in range; 1 not diffed.

- **2026-09-01** `c6a937922d10`: 11 breaking, 31 info
  - added `#/components/schemas/WhatsappSenderInputRegistrationMethodEnum` to the `method` request property `allOf` list
  - removed the enum value `SMS` of the request property `method`
  - removed the enum value `VOICE` of the request property `method`
  - the `method` request property type changed from `string` to no type
  - …38 more
- **2026-08-18** `c78a716de420`: 1 info
  - api operation id `SendersController_register_v1` removed and replaced with `WhatsappSendersController_register_v1`

[Operation history](https://skmtc.dev/sinch/apis/provisioning-api/changes/v1/projects/:projectId/whatsapp/senders/:senderId/register/post.md)

---

[API](https://skmtc.dev/sinch/apis/provisioning-api.md) - [All operations](https://skmtc.dev/sinch/apis/provisioning-api/llms.txt) - [OpenAPI document](https://skmtc.dev/sinch/apis/provisioning-api/revisions/90d78b3a8575?raw)