Understanding SMS lengths and 'units'

A standard SMS can be up to 160 characters in length using the 'Basic' character set. If your message exceeds 160 characters, it becomes a multi-part message which means:

• The message is split into parts of 153 characters each (the extra 7 characters are used for stitching the message together). 

• Even though it's split in the background, the recipient will see it as one long message on their device.

It is important to keep in mind that the 'Basic' set of characters is limited. Some special characters in the 'Basic Extended Set' count as two characters in a non-unicode message e.g. ^\[~]|€{}

Anything outside of the 'Basic' and 'Extended' set forces the message to be sent as unicode.

If your SMS includes any characters outside the standard 7-bit set, such as emojis or special symbols, it will be sent as a Unicode message. This affects the character limits and how your message is billed: 

• A single unicode message is up to 70 characters. 

• If you exceed 70 characters, it becomes multi-part, and each part is limited to 67 characters due to encoding headers. 

For more in depth information, please see: https://en.wikipedia.org/wiki/GSM_03.38 

Emoji Considerations:

Adding just one emoji will convert your entire message to Unicode. Most emojis count as 2 unicode characters, however here's a small set that are a single character and some are more complex: 

• A 'coloured thumbs up' emoji uses 4 characters as it is both a colour symbol followed by the thumbs up symbol.

• The 'family' emojis are made up of 4 different symbols (man, woman, child, child) and can use up to 8 characters.