Text messages from a 5 digit number are known as short code messages and typically come from businesses or services. The best way to unsubscribe from these unwanted messages is to reply any of the following: STOP, END, QUIT, CANCEL or UNSUBSCRIBE.

A short code, or an SMS short code, is an abbreviated phone number that is 5 or 6 digits in length. Short codes are usually used to send SMS and MMS messages with product discounts, passwords, text-to-win sweepstakes, and more. These numbers are “short” by definition, so they’re easy to remember when sending a text message.

An SMS short code, is a 5 or 6-digit number that businesses use instead of the regular 10-digit “from” number for SMS marketing campaigns. These short codes are great for mass-text message sending as they have a fast per-second send speed.

A short code is a 5 or 6 digit phone number that is used to send text messages at scale. People opt into SMS marketing programs by texting a word or phrase known as a "keyword" to a short code. They are meant to be shorter than normal phone numbers to make the opt-in process easier.