SMS Regulations for USA

There are strict rules in regulating SMS marketing in the United States of America. The governing body for this is CTIA. It is vital that senders follow these regulations when carrying out SMS marketing.

Some of the restrictions (applicable for long numbers only) are:


Message format

Text messages sent in the United States has to be of a standard text length – 160 characters. There is a 70 character limit on Unicode per SMS.

The symbol for Euro (€) along with binary and concatenation are not supported.


Sender ID

A sender can’t use alphanumeric or other numeric code, but only long number or short code to send SMS.

Because of this, the sender’s FROM address must have their pre-approved US sender number typed in the international format.


Message content

Messages cannot contain inflammatory, offensive or harmful content. The message content has to be minor friendly if the intended audiences are minors.

Also, repeated usage of keywords and URLs may result in your messages being flagged as spam and networks may block them.



An opt-in consent from recipients is necessary before you can start sending out SMS marketing messages.



Every marketing message from the sender must contain the option for the recipient to opt-out.

Senders are also compulsorily supposed to use Two-way numbers for SMS marketing as the recipients can unsubscribe whenever necessary.


Frequency of messages

It is recommended that you buy additional numbers if you intend to send high frequency messages.

If you send more than one message/second on a single number, the carriers can reject your messages.

For long numbers, message volume is 5000/day, and sending more than this limit can get the sender number blocked. For two way SMS numbers, two way communication (traffic) is expected from the carriers.


Read more: CTIA