Здесь необходимо прояснить несколько вопросов относительно СМС во избежание проблем с биллингом.
Ограничение количества знаков
Количество знаков в СМС ограничено. Если сообщение оказывается длиннее положенного, оно автоматически разбивается на несколько сообщений. Биллинг осуществляется за каждое сообщение.
Character encoding
The number of characters in a message depends on the type of encoding. The standard Latin alphabet encoding (GSM 03.38), used for English and some other European languages, includes a limited number of symbols. If only these symbols are used, then the message is 160 symbols long. But if at least one non-standard symbol is used, even accidentally, then the whole message is re-encoded and shortened up to 70 characters. As a result, the number of messages to be sent will increase, and the billing will increase accordingly.
To avoid this situation, it is key to use only standard symbols. Here is a table of acceptable GSM 7-bit default alphabet (taken from https://en.wikipedia.org/wiki/GSM_03.38).
LF is a Line Feed control.
CR is a Carriage Return control, or filler.
ESC is an Escape to extension table (maps to NBSP).
SP is a Space character.
FF is a Page Break control. If not recognized, it shall be treated like LF.
CR2 is a control character. No language specific character shall be encoded at this position.
SS2 is a second Single Shift Escape control reserved for future extensions.
Note
It is very easy to pick up a wrong symbol by mistake, for instance, when copying the text from Microsoft Word, especially minor symbols, like ‘ (apostrophe) or “ (quotation marks). Yet, if this happens, the system will react with a warning before sending the SMS.