SMS Character Limit
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The character limit for a single SMS message is 160 characters. However, most modern phones and networks support concatenation; they segment and rebuild messages up to 1600 characters. Messages not using encoding are limited to 70 characters.
When you send a SMS message over 160 characters, the message will be split. Large messages are segmented into 153 character segments and sent individually, then rebuilt by the recipient's device. For example, a 161-character message will be sent as two messages, one with 153 characters and the second with 8 characters.
If you include , such as Chinese script, in SMS messages, those messages have to be sent via encoding. Messages containing any UCS-2 characters are limited to 70 characters and will be concatenated into 67 character message segments, even if the messages contain fewer than 160 characters.
SMS is a standardized communication protocol that enables devices to exchange short text messages and was defined as part of the . Originally, it was designed to "fit in between" existing signalling protocols, which is why SMS length is limited to 160 seven-bit characters. It was subsequently codified into the that transmits SMS and is limited to precisely 140 bytes (or 1120 bits).
But things get tricky because GSM-7, the original charater set designed for SMS, only has the ability to denote 128 different characters in those 7 bits. So if you want to include more Latin or non-Latin scripts, you'll need to use UCS-2.
A common mistake is to inadvertently use a UCS-2 character, thinking it's GSM-7 character. GSM-7 isn't a supported character set in many text editors. The classic mistake is to use "curly quotes" not realizing that they're part of UCS-2 and not GSM7.
We recommend that you check any mass messages in before you send them out. It will flag any UCS-2 characters to avoid you being double-charged for messages. If you use Local mail, you can see whether a message was encoded as UCS-2 or GSM7 by viewing an individual message in your sms logs.
If you need any further Help During your Integration or questions related to technical know-how, you can reach out to our support team at support@localmail.io