According to the GSM (Global System for Mobile Communication) encoding standard, the length of one SMS is capped at 160 characters. The standard defines a GSM 03.38 charset that goes through the GSM 7-bit default encoding that is mandatory for GSM handsets and network elements. If a message has any characters that are not defined in this alphabet, they go through a different encoding system, called the GSM 8-bit where the length of an SMS is only 70 characters.
If you find yourself paying for more than you know you sent, it might mean that your message is using a unicode character, i. e a character that is not defined in the GSM 03.38 charset. In this case, the GSM 8-bit encoding process will be used and your message will be chopped up and sent 70 characters at a time.
The GSM 03.38 Default Charset
These are the characters that are defined in the standard. The length of one SMS will be up to 160 characters if you write your message the characters below:
@ £ $ ¥ è é ù ì ò Ç Ø ø Å å ∆ _ Φ Γ Λ Ω Π Ψ Σ Θ Ξ Æ æ ß É ! ” # ¤ % & ’ ( ) * = , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? ¡ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Ä Ö Ñ Ü § ¿ ` a b c d e f g h I j k l m n o p q r s t u v w x y z ä ö ñ ü à
This standard does have an extension that accommodates for more symbols. However, these new symbols take up two regular characters and not just one
^ { } \ [ ~ ] | €
With this in mind, here are a few ways in which you can fit more content into your SMS without incurring unexpected charges.
Know the characters that you can use freely
These are the characters in the GSM 03.38 charset. Using only these characters will ensure that the length of your SMS is up to 160 characters. Make sure to write your messages with these characters to make the most out of an SMS.
Get crafty
Instead of using symbols like the curly bracket that take up two spaces, replace those with normal brackets and save space. You can also replace USD or EUR with their corresponding free up more space.
Use a SMS character counter
There are many SMS character counters out there than can help you figure out how many characters are in your SMS. There are also some invisible unicode space characters that appear like a regular space that end up forcing your maximum SMS length to reduce to 70 characters. The use of online free SMS Character counter tools can help you spot a lot of these.
Steer clear of unicode characters
Remember that even one unicode character in your message is enough to enforce a different encoding process to be done on your message. Know the right characters and use tools to help you identify these characters and amend appropriately
Shorten your links
Not only can full length links take up more space, many special characters can appear on them and therefore limits your space. Make it a good habit to shorten your links. There are many online tools that can help with that.