---
title: "Subscribe to User Defined Messages for a given Call SID."
method: POST
path: "/2010-04-01/Accounts/{AccountSid}/Calls/{CallSid}/UserDefinedMessageSubscriptions.json"
tags: ["Api20100401UserDefinedMessageSubscription"]
---

# Subscribe to User Defined Messages for a given Call SID.

`POST /2010-04-01/Accounts/{AccountSid}/Calls/{CallSid}/UserDefinedMessageSubscriptions.json`

Subscribe to User Defined Messages for a given Call SID.

## Path parameters

- `AccountSid` string, required
- `CallSid` string, required

## Response `201`

Created

- ApiV2010AccountCallUserDefinedMessageSubscription
  - `account_sid` string, nullable — The SID of the [Account](https://www.twilio.com/docs/iam/api/account) that subscribed to the User Defined Messages.
  - `call_sid` string, nullable — The SID of the [Call](https://www.twilio.com/docs/voice/api/call-resource) the User Defined Message Subscription is associated with. This refers to the Call SID that is producing the User Defined Messages.
  - `sid` string, nullable — The SID that uniquely identifies this User Defined Message Subscription.
  - `date_created` string, date-time-rfc-2822, nullable — The date that this User Defined Message Subscription was created, given in RFC 2822 format.
  - `uri` string, nullable — The URI of the User Defined Message Subscription Resource, relative to `https://api.twilio.com`.

## Changes

- **2024-04-18** (v2010) `cf63f47f41aa` — 4 breaking
  - removed the enum value `DELETE` of the request property `Method`
  - removed the enum value `HEAD` of the request property `Method`
  - removed the enum value `PATCH` of the request property `Method`
  - removed the enum value `PUT` of the request property `Method`

[Change history](https://skmtc.dev/twilio/apis/api-v2010/changes/2010-04-01/Accounts/:AccountSid/Calls/:CallSid/UserDefinedMessageSubscriptions.json/post.md)

---

[API](https://skmtc.dev/twilio/apis/api-v2010.md) · [All operations](https://skmtc.dev/twilio/apis/api-v2010/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/twilio/api-v2010/revisions/6b6ffccef14c/schema)