Why is it that a text message is 160 characters long? And how many characters can a sender name contain? Find out in this blog post where you can also read about merging SMS messages and what characters you can use in the sender name.
Why is the limit on SMS messages 160 characters?
Anyone who had a mobile phone in the late 90s and early 00s will remember how difficult it was to stay under the 160 character limit of 1 SMS message. Creative abbreviations and concise language were used extensively to keep the small counter in the top right corner of the screen below the golden limit. If the counter exceeded 160, the SMS message was split into several messages, which was reflected in the mobile bill and not least the message in the SMS message.
"Thank goodness it's not like that anymore!" you might be thinking, but the 160 character limit for a text message still applies. (Yes, the industry is a bit old school, but this has its charm). We just don't notice it because SMS messages today are automatically merged if they exceed 160 characters.
Postcards and teletex form the basis for SMS length
SMS messages have always been limited to 160 characters (including spaces), and there's a special story behind that.
Back in 1985, Friedhelm Hillebrand - the then chairman of the non-voice service committee of the Global System for Mobile Communications (GSM) - had been tasked with determining the maximum number of characters an SMS message could contain. So he sat down in front of the typewriter and started typing a bunch of random sentences. His aim was to find out how many characters he used per sentence on average. He found that he used just under 160 characters per sentence.
Hillebrand passed the result on to the other committee members, who were not 100% convinced. To support his findings, Hillebrand found a stack of postcards, all written in just 150 characters. He also analysed a large number of messages sent via Telex - a telegraphic network for business people - which showed that on average 150 characters were used, even though an unlimited number of characters were available. Hillebrand's research convinced the committee members that 160 characters was the right limit, and it's been that way ever since.
inMobile's SMS gateway can handle 1377 characters per message
The 160 characters per SMS message still applies today, but luckily our phones have become so intelligent that they automatically merge SMS messages so that the recipient sees it as a single message. inMobile's SMS gateway can handle merging up to 9 SMS messages corresponding to 1377 characters per broadcast. The astute reader will have realised that 160 characters x 9 SMS messages are 1440 characters, not 1377 characters. What about the last 63 characters?
This is how telecoms companies use 7 characters to merge two SMS messages. This means that as soon as you type more than 160 characters in a message, 7 of the characters are used to merge the messages. Therefore, you only have 153 characters to work with per SMS message when you exceed 160 characters.
Message sizes (for GSM7)
- 0-160 characters: 1 SMS message
- 161-306 characters: 2 text messages
- 307-459 characters: 3 text messages
- 460-612 characters: 4 text messages
- 613-765 characters: 5 text messages
- 767-918 characters: 6 text messages
- 920-1071 characters: 7 text messages
- 1073-1224 characters: 8 text messages
- 1225-1377 characters (max): 9 SMS messages
Fortunately, 153 characters x 9 gives you plenty of room to express yourself, but you should remember that it's still important to communicate concisely when using SMS. You can read more about sharp SMS communication in the blog post here: Sharp communication.
How many characters can a sender name contain?
When you receive an SMS message, the sender name, also called Sender ID, will always appear at the top of the message correspondence on your phone. A regular SMS message sent from one phone to another will always show a phone number if you have not created the contact in your phone book. With an SMS gateway like inMobile, you have the advantage of being able to decide what the sender name should be. For example, you can brand your company name so that the recipient can immediately recognise that the text message is from you. We think that's pretty smart ourselves.
SMS is quite a few years old, and many of the standards set when the first SMS message was created in the early 90s still apply today. This also applies to how many characters a sender name can contain.
Alphanumeric sender name (Letters and numbers): max. 11 characters
Numeric sender name (Numbers only): Max 15 characters
ATTENTION!
An alphanumeric sender name can contain upper and lower case letters and numbers. Do NOT use special characters or emojis.
Can you reply back to a sender name consisting of text?
No, unfortunately it is not possible for the recipient to reply back to a sender name with text. This type of sender name is only suitable for 1-way communication. For example, it could be an operational message or a reminder. However, if you want the recipient to be able to reply to your SMS message, you need to use a virtual number and a keyword. Read more about 2-way communication here.
Restrictions from country to country
If you're sending abroad, there may be some restrictions on what you can write in the sender name. Therefore, always check what restrictions there are in the country in question. If you are in doubt, you can always write to our support in the chat here.
