A normal SMS consists of 160 characters using the GSM 7-bit alphabet
This is a limitation in the format/protocol through which SMS is sent.
FTo be able to send longer messages than that, the message is divided into parts of 153 characters and sent as separate text messages. 7 characters are sent that tell the phone in which order the parts should be put together, so that the phone can display the message as a single long text at the recipient.
This means that if you send a text longer than 160 characters, it will cost more than just an SMS.
If you are unsure of how long your message will be, it is recommend that you test sending a message to yourself first. In your logs, you can then see how many SMS parts your message was split into. Feel free to contact us if you want help checking this.
Mailings using the address book
Each address book can have its own settings that add text to the message. The added text should also be included in the total number of characters sent. The editor in the Toolbox cannot count these, it only counts the characters in the message box.
If you have a text in the “SMS Header” – field, that text will be added in the beginning of the message. If automatic unsubscribe notification is activated, the system also adds a text at the end of your message, with information on what the recipient should do if they wish to unsubscribe from further mailings.
Depending on the type of sender you have in the address book, different numbers of characters will be added:
– Short code 72080, Reply SMS and Own number as sender means that the final text will be approx. 38 characters long: “— Answer STOP to unsubscribe.”
– A text as sender/originator causes the end text to be approx. 34 characters long: “— Unsubscribe: Reply stop to 72080”
If you are unsure of how long your message will be, it is recommend that you test sending a message to yourself first.
GSM 7 alphabet
Character set GSM 03.38 is the usual one for SMS and creates the GSM 7 bit alphabet.
According to wikipedia, the following characters are accepted in the above alphabet:
Then there are some characters that make the message longer without making it Unicode, according to Wikipedia they are the following characters:
When does it become Unicode?
When the message contains characters that are not in the GSM 7-bit alphabet, it becomes Unicode.
Then it can be covered by different character tables, the most common being GSM 8 bit.
There are, for example, the small Greek letters and many Latin letters (for example: š, ž, –, ´and “) that are missing in the character collection above. Emoticons/emojis belong to the GSM 16 bit table, which means that even more characters are used “per character”.
Then there are additional Unicode formats that make the maximum number of characters even more modest, they are not so common and therefore not specified here.
Messages sent as GSM 8 bit instead of GSM 7 bit can be a maximum of 70 characters per SMS instead of 160 characters.
When it comes to concatenated/multipart messages, there will be a maximum of 153 parts in regular SMS and 67 characters in Unicode messages.
Max number of characters in a concatenated/multipart Unicode message is 1072 (it will be 16 parts long) provided it is GSM 8 bit Unicode.