---
title: "Upload attachment"
method: POST
path: "/v1/projects/{projectId}/registrations/{registrationId}/attachments/{attachmentId}"
tags: ["registrations"]
---

# Upload attachment

`POST /v1/projects/{projectId}/registrations/{registrationId}/attachments/{attachmentId}`

## Request

- Base URL: `https://senderid.registrations.api.sinch.com`
- URL: `https://senderid.registrations.api.sinch.com/v1/projects/{projectId}/registrations/{registrationId}/attachments/{attachmentId}`
- Auth: OAuth 2
  - Client credentials
  - Token URL: `https://auth.sinch.com/oauth2/token` scopes: `write`

Through this endpoint, attachments can be added to registrations. The required attachments for each registration can be retrieved from the get policy endpoint.

## Path parameters

- `projectId` string, required
- `registrationId` string, required
- `attachmentId` string, required

## Request body `multipart/form-data`

- string, binary

## Response `200`

Document uploaded successfully

## Other responses

- `400`: Registration status is not valid for including attachments
- `404`: registration/document not found
- `413`: Document is too large to upload

---

[API](https://skmtc.dev/sinch/apis/sinch-sender-id-registrations-api.md) - [All operations](https://skmtc.dev/sinch/apis/sinch-sender-id-registrations-api/llms.txt) - [OpenAPI document](https://skmtc.dev/sinch/apis/sinch-sender-id-registrations-api/revisions/fe69a3ac7d43?raw)