Introduction
An SMS is technically limited to a certain number of characters. It is possible to send a longer SMS by hanging up, invisibly for the user, several SMS messages between them.
Good practices within an SMS
The maximum number of characters to be included in SMS content therefore depends on the number of SMS messages set up and the type of characters used.
Beware, it should be noted that among the characters counted are included the STOP mention and the personalisation. It will always be the STOP mention and the longest personalisation that will be taken into account when calculating the size of an SMS.
- If UTF-8 is enabled, and the SMS content contains special characters, then:
- 1 SMS = 70 characters,
- 2 SMS = 134 (67 x 2),
- n SMS = 67 x n.
- If UTF-8 not enabled, or content without special characters, then:
- 1 SMS = 160 characters,
- 2 SMS = 306 characters (153 x 2),
- n SMS = 153 x n.
Concatenated SMS messages are limited to 153 x n characters. The 7-character delta corresponds to a character string that will link the two, three, n SMS to concatenate them into a single SMS. The recipient will obviously not see this string of characters and will instead see a long message displayed.
Conclusion
This number of characters is indicated during the creation of SMS content.