> ## 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.

# Key US regulations

> Learn about key SMS/MMS regulations in the United States.

# Key US regulations

Learn about key SMS/MMS regulations in the United States.

## TCPA (Telephone Consumer Protection Act)

The TCPA is the primary federal law governing SMS and MMS messaging in the United States.

### Key requirements

* **Express written consent**: Must obtain written consent before sending messages
* **Opt-out mechanisms**: Must provide easy unsubscribe options
* **Do Not Call Registry**: Respect the National Do Not Call Registry
* **Time restrictions**: No messages before 8 AM or after 9 PM local time

## CAN-SPAM Act

The CAN-SPAM Act applies to commercial email and some SMS messages.

### Key requirements

* **Clear identification**: Clearly identify your business
* **Accurate subject lines**: Use accurate message content
* **Opt-out**: Provide clear unsubscribe instructions
* **Honor opt-outs**: Process opt-outs within 10 business days

## State laws

Many states have additional messaging laws:

* **California**: California Consumer Privacy Act (CCPA)
* **Florida**: Florida Do Not Call Act
* **New York**: State-specific regulations
* **Texas**: Texas Do Not Call List
* **And more**: Check your state's specific laws

## FCC regulations

The Federal Communications Commission (FCC) enforces TCPA and related regulations.

### Recent updates

* Enhanced opt-in requirements
* Stricter consent requirements
* Increased penalties for violations
* Expanded scope of regulations

**See also:**

* [General US content restrictions →](/help-and-reference/deliverability-compliance/united-states-sms-mms-compliance/general-us-content-restrictions)
* [US SMS/MMS compliance →](/help-and-reference/deliverability-compliance/united-states-sms-mms-compliance/us-sms-mms-compliance)