Default / GSM7 encoding
A default (GSM7) encoded message can have a length of max 160 characters. If you put more characters in, the message will be split up into several parts. This kind of message is called long messageor concatenated message. Each part can of a concatenated message can consist of 153 characters at max. This shorter amount is due to the fact, that the other 7 characters are “eaten up” by informational bytes which tell the end user device that its a concatenated message and further information, like total part count, current part count, etc…
UCS2 / Unicode encoding
A UCS2 or Unicode encoded message can have a length of max 70 unicode characters (fyi, each one is worth 2 bytes). If you put more characters in, the message will be split up into several parts. This kind of message is called long message or concatenated message. Each part can of a concatenated message can consist of 67 characters at max. This shorter amount is due to the fact, that the other 3 unicode characters are “eaten up” by informational bytes which tell the end user device that its a concatenated message and further information, like total part count, current part count, etc…
Binary encoding
A Binary encoded message can have a length of max 140 characters/bytes. For the Text parameter please only use ASCII-Characters (8-bit). See Binary SMS for a vCard example.
Binary messages can also contain more than 140 characters/bytes and are then, similar toGSM7 and UCS2 messages, split up into multiple parts. Each part can then contain at max 134 characters/bytes.
Cost Remarks
If a message will be split up into several parts (concatenated message) you will be charged for each part, as each part is a real SMS. If a message has been split up you can determine by examining the messageIds return parameter; it will contain more than 1 ID if the message had to be split.