---
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`.

---

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