What's an SMS Short Code?
A short code number (or short code) is a special telephone number designed for high-throughput, two-way messaging. These short codes support sending and receiving messages using both the text-only Short Message Service (SMS) and multimedia-capable Multimedia Messaging Service (MMS). Twilio offers short codes in 14 countries. These codes have between three and seven digits, making them shorter than their ten-digit long code counterparts.
If you plan to send more than more than five hundred text messages a day from a long code, carriers might mark your messages as spam. To permit high volume and throughput of texts, carriers provide short code numbers. When you want to send thousands of messages, use short codes.
Developers use short codes for the following use cases:
- Marketing and promotions
- Alerts and notifications
- Two-factor authentication
To find the owner of a US short codes, you have three options:
- Reply to the message with
HELP. This returns the company who sent the message or the company providing the SMS service. This works in countries outside the US as well. - Go to the Telephone Wiki SMS page. It lists some short codes.
- Go to the Reverse Numbers site. This site provides more details for a fee.
If you want a US short code, check its availability with the short code lookup tool.
To use a short code, you pay a setup charge, a quarterly lease, and a per-message cost.
Each carrier sets their own charges for SMS and MMS messages, both incoming and outgoing. To send these messages, Twilio charges a very small additional fee.
Twilio can help obtain a short code from Twilio or migrate an existing one.