Short message service (SMS) is a service available on most digital mobile phones that permits the sending of short messages (also known as SMSes, text messages, messages, or more colloquially texts or even txts) between mobile phones, other handheld devices and, even, fixed-line phones. SMS was originally designed as part of the GSM digital mobile phone standard, but is now available on a wide range of networks, including 3G networks.

The first SMS is believed to have been sent in December 1992 from a personal computer (PC) to a mobile phone on the Vodafone GSM network in the United Kingdom.