By default, 160 characters can be sent on a single SMS message. If you want to send a long SMS messages you will have to enable concatenation. This will allow the SMS message to be spanned over two or three message parts. In this case please note that you will be able to set only 153 characters per message part, as the other 7 characters are used for the concatenation information.
When concatenation is used, please note you will be billed per message part.
Also note the following:
GSM is a 7 bit character set. In order to get as many of the ASCII characters mapped, non printable characters 0x00-0x1F have been used to represent some of the characters. Others are represented by closest character prepended by an ESC (escape character). There are many complex reasons why GSM specification writers chose this method.
In this character set, some characters are mapped into 2 characters ("ESC" + the character). The following characters will take 2 spaces each in SMS text messages:
Hex Description
0x1B0A Form feed
0x1B14 Circumflex accent ^
0x1B28 Left curly bracket {
0x1B29 Right curly bracket }
0x1B2F Backslash \
0x1B3C Left square bracket [
0x1B3D Tilde ~
0x1B3E Right square bracket ]
0x1B40 Vertical bar |
0x1B65 Euro sign
