Multipart SMS

We bill per 160 characters which is the GSM standard:

If your message length exceeds the standard 160 characters, then it will be sent across multiple SMSs. Just remember that you’re billed for each SMS part and that you’ll only have 153 characters per part, including the first part.

Standard SMS / GSM practices are applied on our platform. Messages 160 characters or less using the GSM 3.38-character set will be billed as one message, higher character count will be billed as follows:

Characters	Message Parts
160 characters or less	1 message part
153 - 306	2 message parts (153 x 2)
307 - 459	3 message parts (153 x 3)
460 - 612	4 message parts (153 x 4)
613 - 765	5 message parts (153 x 5)
766 - 918	6 message parts (153 x 6)
919 - 1071	7 message parts (153 x 7)
1072 - 1225	8 message parts (153 x 8)

This continues upwards. We can cater for up to 8 parts, but for general usage and capability with older feature phones, we recommend a max of 3 - 5.

One might expect that if a single SMS can hold 160 characters, a 320-character message would take two physical SMS. This is not the case.

When multipart SMS technology is used, only 153 characters fit into a single SMS because some space is needed for the segmentation information that can be used to reassemble the message parts in the correct order. So if a 320-character message is sent, it would take 3 SMS. The first two would hold 153 characters, and the last one would hold the remaining 14 characters.