---
title: "Attach a message to an existing application"
method: POST
path: "/v1/applications/{application_request_id}/messages"
tags: ["Attach a message"]
---

# Attach a message to an existing application

`POST /v1/applications/{application_request_id}/messages`

## Request

- Base URL: `https://businessgateway.landregistry.gov.uk/bg2/api`
- URL: `https://businessgateway.landregistry.gov.uk/bg2/api/v1/applications/{application_request_id}/messages`
- Auth: HTTP basic
- TypeScript: <https://skmtc.dev/hm-land-registry/apis/v1-0-submit-an-application-to-change-the-land-register-api-s/docs/v1/applications/:application_request_id/messages/post.ts> (a function with typed inputs; its response is checked against the schema)

Application information API - Get the information about an application

## Path parameters

- `application_request_id` string, required

## Request body

- AttachAMessageRequest: The request to send to the endpoint to request an upload URL
  - `data` object, required
    - `message_text` string, required: The content of the message to be attached

## Response `202`

Accepted

## Other responses

- `400`: Bad Request
- `401`: Unauthorised - an access token is required
- `404`: Application creation request not found in the system
- `500`: Internal Server Error

## Changes

- **2025-11-07** `04719f6cbb9c`: 1 info
  - api operation id `Attach a message` removed and replaced with `attach_a_message_v1`

[Operation history](https://skmtc.dev/hm-land-registry/apis/v1-0-submit-an-application-to-change-the-land-register-api-s/changes/v1/applications/:application_request_id/messages/post.md)

---

[API](https://skmtc.dev/hm-land-registry/apis/v1-0-submit-an-application-to-change-the-land-register-api-s.md) - [All operations](https://skmtc.dev/hm-land-registry/apis/v1-0-submit-an-application-to-change-the-land-register-api-s/llms.txt) - [OpenAPI document](https://skmtc.dev/hm-land-registry/apis/v1-0-submit-an-application-to-change-the-land-register-api-s/revisions/6964bf9fc289?raw)