> ## Documentation Index
> Fetch the complete documentation index at: https://help.cloudtalk.io/llms.txt
> Use this file to discover all available pages before exploring further.

# "HELP" and "STOP" Keywords in U.S. SMS Messaging

> Automatic SMS compliance for STOP and HELP keywords in U.S. messaging

> [!NOTE]
>
> This article explains how CloudTalk automatically handles SMS keyword compliance (like **STOP** and **HELP**) for U.S. numbers. You don’t need to take any action - these rules are built into the system and apply by default to all U.S. SMS-enabled numbers in your account.

**User level:** Admin

***

When sending SMS messages via CloudTalk via US numbers, certain industry-wide standards are automatically applied to ensure compliance and consumer protection. Specifically, all U.S. SMS campaigns must support the keywords **HELP** and **STOP**.

## What Are "HELP" and "STOP"?

U.S. carriers require all messaging programs, especially those using short codes, toll-free numbers, or A2P 10DLC (Application-to-Person) routes, to recognize and properly respond to two specific keywords:

* **STOP**

  * When someone replies with **STOP**, they are automatically unsubscribed from receiving future SMS messages from that number. CloudTalk handles this opt-out process on your behalf and ensures no further messages are sent to the user.

  * alternative keywords: **UNSUBSCRIBE**, **CANCEL**, **END**, or **QUIT**

  * upon the unsubscription, sender will recieve the confirmation SMS and SMS sendout from Cloudtalk will be prevented.

    ![](https://mintcdn.com/cloudtalk/g8s2E4Yk8cWS5656/images/help-center/articles/11513804/8fade825dc7c-screenshot-20250605-084413-messages.jpg?fit=max\&auto=format\&n=g8s2E4Yk8cWS5656\&q=85\&s=2189f0cf76fd95401980b0ce8155571c)

* **HELP**

  * When a user sends **HELP**, they receive an automated response providing support contact information or assistance details. This response is automatically generated based on standard U.S. messaging guidelines.

  * alternative keywords: **INFO**, **SUPPORT**, or **ASSIST**

> [!WARNING]
>
> 💡Opting out via keyword **applies only to the specific phone number that the STOP message was sent to**. Unless the contact unsubscribes from all numbers, you can still send SMS messages to them from other SMS-enabled numbers in your account.

***

### How a User Can Resubscribe

If someone has opted out using **STOP** or a related keyword, they can choose to resubscribe at any time. To do so, they simply need to send the keyword:

* **START**

Sending **START** reactivates the conversation, allowing them to receive messages from your number again. Carrier automatically recognizes and processes this request.

***

*Need help or have a question?* Just reach out through our [Support portal](https://support.cloudtalk.io/hc/en-us/requests/new?ticket_form_id=26305535257884) — we’re here for you.


## Related topics

- [Registering Standard USA Numbers for Messaging (A2P 10DLC)](https://help.cloudtalk.io/en/articles/7222203-registering-standard-usa-numbers-for-messaging-a2p-10dlc.md)
- [Text Messaging](https://help.cloudtalk.io/en/articles/3765739-text-messaging.md)
- [Cannot Send or Receive SMS](https://help.cloudtalk.io/en/articles/12959333-cannot-send-or-receive-sms.md)


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