Information About SMS Character Encoding, Language Support and Message Lengths

The world of SMS Messages are a little more complicated than meets the eye. This article explains some of the different types of SMS Messages and limitations that can occur. These limitations are not caused by Elvanto, but by the SMS Companies themselves.

We have a created a table to help you determine which SMS Companies support the different types of messages we outline below.

Please note that the information we give is only a guide. Results may vary depending on your mobile carrier, language and country. If you plan to use different languages or advanced characters, we suggest you contact the SMS Company you are interested in to find out more about their support.

Character encoding

Different SMS Companies have limitations on what characters you can send in an SMS Message. The characters you use will also affect the type of message that is sent, and therefore could affect the price of the SMS Message.

The GSM character set

GSM is a character set used within GSM based mobile phones and counts for most mobile phones available today.

The characters include the Latin alphabet, numbers, and other symbols found on your keyboard such as ! @ # and so on. It also includes non-english characters such as Ä Ø Ö etc . However, some SMS providers have limited support for these.

The full GSM character set list can be found in this Wikipedia article.

The ‘GSM Extended’ character set

Most SMS Companies also allow for extended GSM characters to be used within SMS Messages. The extended characters include: { } [ ] | ^ ~ €.

Refer to the provider table for details on which providers have support for these extended characters.

Even if the SMS provider does support these characters, we recommend doing a test before using them as results may vary depending on your mobile carrier and country. For instance, the Euro currency sign only works in some countries on some mobile carriers.

Unicode

The unicode standard allows you to go beyond the GSM character sets in order to support a wide range of languages and technical symbols.

For example, if you’d like to send an SMS message in Japanese, you can do so, but it will be sent as a unicode message.

Unicode messages can only contain half the characters of a normal text message. More about that below.

Unicode support is limited depending on your SMS Company, mobile carrier and country. Refer to the provider table for details on which SMS Companies have support for unicode messages.

Important Note: Before choosing an SMS Company, we suggest you contact the SMS companies that support unicode messages to find out more about their character support for your language and the country you are sending messages to.

Message Length

The length of a message calculated in Elvanto is a guide only. If you are using dynamic placeholders in your message, this will affect its length. For example %firstname% is 10 characters long. When a message is sent to Ben, the message will be 7 characters less in length due to the first name only being 3 characters long.

The typical length of an SMS Message is 160 characters, however, if you use any characters from the GSM Extended character set above, they count as 2 characters each. It’s a bit strange, but all SMS Companies seem to do it this way.

When you send an SMS Message that is over 160 characters, the SMS Company will convert the SMS into a multi-part message. Multi-part messages are limited to 153 characters per message part. A mulit-part message is in fact the same as sending multiple SMS Messages, however, modern mobile handsets are able to ‘stitch’ multi-part messages back into a single, seamless message. Keep in mind that every message part of a multi-part SMS message costs you an SMS credit.

If you send an SMS message that includes one or more unicode characters, the length per message is reduced to 70 characters. If you go over the 70 character limit, it will be sent as a multi-part message and each message part is reduced to 67 characters.

If an SMS company does not support multi-part, it will simply send multiple SMS Messages which will not be “stitched” back into a single message. Messages might be cut off where they have been split, but they should still be readable by recipients.

Last Updated: 16th November, 2016