Skip to content

Encoding and count of characters

Generally, the SMS text has to be transfered with UTF-8 encoding to the gateway. You have the option to use the parameter “is_unicode” to decide if you want to send a normal 7 bit or UCS-2 SMS.

The basic character set contains all characters that can be transmitted with a normal 7 bit SMS. Each of this characters counts as 1 character. The extended character set can also be transferred, but requires 2 characters for transmission. SMS which contain more than 160 characters are delivered to the handset as multiple SMS, each with 153 characters, and concatenated by the phone to one message. If you send an SMS explicitly with the GSM 03.38 charset and your message contains characters which are not part of the GSM charset, our system will try to convert your text using transliteration.

Basic Character Set

0x000x100x200x300x400x500x600x70
0x00@ΔSP0¡P¿p
0x01£_!1AQaq
0x02$Φ2BRbr
0x03¥Γ#3CScs
0x04èΛ¤4DTdt
0x05éΩ%5EUeu
0x06ùΠ&6FVfv
0x07ìΨ7GWgw
0x08òΣ(8HXhx
0x09ÇΘ)9IYiy
0x0ALFΞ*:JZjz
0x0BØESC+;KÄkä
0x0CøÆ,<LÖlö
0x0DCRæ-=MÑmñ
0x0EÅß.>NÜnü
0x0FåÉ/?O§oà
  • LF is a Line Feed control.
  • CR is a Carriage Return control, or filler.
  • ESC is an Escape control.
  • SP is a Space character.

Extended Character Set

0x000x100x200x300x400x500x600x70
0x00
0x01
0x02
0x03
0x04^
0x05
0x06
0x07
0x08{
0x09}
0x0AFF
0x0BSS2
0x0C[
0x0DCR2~
0x0E]
0x0F|
  • 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.

With UCS-2 it is possible to transmit 1,112,064 characters. These characters represent nearly every spoken language. Each character counts as 1 character, but Unicode SMS can only consist of 70 characters, or consist of multiple concatenated SMS, each with 67 characters.

For technical reasons, with one sms only 160 characters of text (70 characters Unicode text) can be transferred. If you send an SMS with more characters, then you send a so-called concatenated SMS. Overlong text messages / Multi-SMS (concatenated SMS, Long SMS) are part messages and transmitted separately. Each part is a separate text message. The receiver converts the parts again into a coherent text. To determine that the message is a concatenated message and which part belongs to which part 7 characters (or 3 in Unicode) of the available characters are needed. This is the reason why one part of an overlong SMS can only consist 153 characters (or 67 for Unicode) of your text. The maximum is 1530 characters with one concatenated message (or 670 characters for Unicode).