Clickatell Platform gives you the option to specify in which character set you are submitting your messages. If the charset is not specified, all messages will be encoded in the UTF-8 Unicode standard by default. The UTF-8 library covers almost all written characters and symbols for all major languages. It was also designed for backward compatibility with ASCII.
A large number of mobile networks support only the GSM character set. The GSM character set is much smaller than UTF-8, so it’s possible that some characters may not be supported.
Our system was developed to automatically determine the encoding needed for optimal delivery of an SMS message. If any characters in your submitted messages are not supported by the mobile network carrier, we will automatically convert the message to the hexadecimal Unicode format required to ensure delivery.
We therefore fully support Unicode encoding with no effort from your side, we do it automatically for you. Messages should be submitted to our platform in text (unconverted format), we’ll handle the Unicode conversion for you when required.
If a message is converted to the hexadecimal Unicode format, fewer characters can be accommodated per message part. With this format, message parts consist of only 70 characters.
Learn more about how multiple message parts (concatenation) works, here.