Concatenated messages are those that require special encoding to fit more characters into a single SMS. Long messages are split into various units by the transmitting device, which is then merged at the receiving end.

Beyond that, each message is priced differently. Concatenation of SMS messages allows a phone to send texts longer than 160 characters. The sender composes a message as usual, but behind the scenes, the phone detects the message length.

If the message is less than or equal to 160 characters, the phone sends a standardized SMS message.