SMS/MMS Regulations for USA

SMS and MMS marketing in the U.S. is strictly regulated by the CTIA, and senders must comply to avoid penalties or message blocks.

Key Restrictions (for long numbers only)

Message Format

• Standard SMS length: 160 characters per message.

• Unicode messages are limited to 70 characters per message.

• The Euro (€) symbol, binary encoding, and concatenation are not supported.

Sender ID

• Only long numbers or short codes can be used—alphanumeric sender IDs are not allowed.

• The sender's FROM address must use a pre-approved U.S. sender number in international format.

Message Content

• Messages must not contain offensive, inflammatory, or harmful content.

• If targeting minors, the content must be appropriate for all ages.

• Excessive use of keywords and URLs can trigger spam filters, leading to message blocks.

Opt-in & Opt-out Requirements

• Opt-in consent is required before sending any SMS/MMS marketing messages.

• Every marketing message must include an opt-out option.

• Senders must use two-way numbers, allowing recipients to unsubscribe at any time.

Message Frequency & Volume Limits

• High-frequency senders should purchase additional numbers.

• Carriers may reject messages if more than one message per second is sent from a single number.

• Daily limit for long numbers: 5,000 messages—exceeding this may lead to number blocking.

• For two-way SMS/MMS numbers, carriers expect balanced inbound and outbound traffic.

Following these regulations ensures compliance and prevents disruptions in SMS marketing campaigns.