How many SMS credits are used?

The number of SMS credits that are used by a message is calculated according to an industry-wide standard, which is based on the actual number of data-packets that are needed to contain the message.

Basic SMS

In the simplest case, an SMS of 160 characters or less uses 1 SMS credit.  For longer messages, some of the data-packet is needed for the "glue" that joins the parts of the message together, and you only get 153 characters for each credit.  

These SMS allow you to use any standard ASCII characters (most of the characters you would find on a typical keyboard), as well as some of the more common accented characters used in European languages, and some special symbols...

à ä å Å æ Æ Ç é É è ì ñ Ñ ò ö ø Ø ß ù ü Γ Δ Θ Λ Ξ Π Σ Ψ Ω ¡ ¿ £ ¤ ¥ §

Special Characters (double length)

There are some special characters that take up twice as much space in the data-packets.  These include...

[ \ ] ^ { | } ~ €

Unicode Characters

To go beyond the standard characters and special characters an SMS can use a universal character set called "Unicode".  When Unicode characters are used, the entire SMS message is encoded using that extended character set, and each character uses up more bits in the data-packet.

In this case a single SMS can only be 70 characters, and longer SMS use up 1 credit per 67 characters.

Entering non-standard characters

Generally speaking, most SMS that you type will not use any special characters, but if you copy and paste from a word-processor (for example) you may end up with special curly-quotes, or a rounded apostrophe (not part of the standard character set).

Apart from pasting, you may also enter some of these characters by using special keyboard tricks to type accent marks (for example).

Why we allow special characters

Whether or not you include special characters in your SMS messages is up to you.  We allow special characters and Unicode in SMS to ensure that you are able to send the message in the way that you want to.  For example, so that names like Carreño can be sent properly.