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

# US SMS/MMS compliance

> Learn about SMS/MMS compliance requirements and best practices.

# US SMS/MMS compliance

Learn about SMS/MMS compliance requirements and best practices.

## Compliance requirements

### Consent

* **Express written consent**: Obtain written consent before sending
* **Clear opt-in**: Use clear opt-in mechanisms
* **Documentation**: Keep records of consent
* **Revocable**: Consent must be revocable

### Opt-out

* **Easy unsubscribe**: Provide easy opt-out options
* **STOP keyword**: Support STOP keyword for opt-out
* **Immediate processing**: Process opt-outs immediately
* **Confirmation**: Confirm opt-out requests

### Message identification

* **Business name**: Include your business name
* **Contact information**: Provide contact details
* **Opt-out instructions**: Include unsubscribe instructions
* **Clear purpose**: State the purpose of messages

## Best practices

### Before sending

* Obtain proper consent
* Verify phone numbers
* Respect Do Not Call Registry
* Check time restrictions

### While sending

* Include opt-out instructions
* Identify your business
* Use appropriate timing
* Monitor delivery rates

### After sending

* Process opt-outs immediately
* Maintain records
* Monitor complaints
* Review compliance regularly

**See also:**

* [Key US regulations →](/help-and-reference/deliverability-compliance/united-states-sms-mms-compliance/key-us-regulations)
* [US voice compliance →](/help-and-reference/deliverability-compliance/united-states-sms-mms-compliance/us-voice-compliance)