The charge for an SMS is based on three things:
- Where you are sending them to, which determines the per-message rate.
(see pricing on the Enfonica website for more information) - How long the message is.
- The content of the message.
Behind the scenes, SMS are sent in individual segments. You are charged for each segment. Each segment has a maximum length, which means the more segments your SMS contains, the more the SMS costs to send.
The basic rule of thumb is, using standard characters, you will be charged for a single SMS if it is 160 characters or less. If using non-standard characters, you will be charged for a single SMS if it is 70 characters or less. Standard characters are characters in the GSM-7 character set. This includes most of the letters, numbers and symbols on the keyboard on your mobile phone. Non-standard characters are everything else, including emojis.
When you exceed the length of a single SMS, the rules change slightly:
If using standard characters, your SMS will be divided into segments, where each segment contains 153 characters. If using non-standard characters, your SMS will be divided into segments, where each segment contains 67 characters.
Here are a few examples that apply the rules stated above:
- A SMS only contains standard characters and is 100 characters long. This is less than 160 characters, so you will be charged for one SMS.
- A SMS only contains standard characters and is 400 characters long. This is longer than 160 characters, so it will be split into segments of 153 characters. It takes three segments to fit 400 characters, so you will be charged for three SMS.
- A SMS contains an emoji and is 50 characters long. This is less than 70 characters, so you will be charged for one SMS.
- A SMS contains an emoji and is 100 characters long. This is longer than 70 characters, so it will be split into segments of 67 characters. It takes two segments to fit 100 characters, so you will be charged for two SMS.