A Guide to SMS Message length
The number and types of characters that are used in your SMS messages determine the cost. This guide walks you through the details.
What is the maximum length of a text message?
A standard text message is 160 characters long but you can send messages that are much longer than 160 characters. With The SMS Works SMS API, you can send messages that are up 1280 characters in length. A standard text message of 160 characters or less (including spaces) will use 1 text credit.
Longer messages use 153 characters for each additional text. The remaining or missing 7 characters are used to ensure that multipart SMS messages are recombined into a single message when they reach the recipient's handset. You can read more about SMS message length in our deep dive.
Do spaces count as characters in a text message?
Yes. The space character when encoded, is an actual character, rather than a ‘blank’, so it uses one out of the 160 available characters.
How much does it cost to send a longer text message?
The cost for multipart SMS messages is simply dependent on the number of text credits used to send the message. For example, if a message is 210 characters long, then 2 text credits will be used. On The SMS Works standard pricing, a text credit costs 3.45 pence + VAT, so 2 text credits costs 6.3 pence + VAT.
How are international messages charged?
International messages, sent outside the UK, use the same number of credits as UK messages. But the cost per credit varies from country to country. Please see our international SMS pricing for specific country costs.
What is the maximum number of characters for the SMS sender ID?
The sender ID is who the message is from and appears at the top of the message on the person's phone.
The maximum number of alphanumeric characters is 11. No spaces are permitted in the SMS sender ID.
Is there anything else that might cause my message to use more than 1 text credit?
Yes. Some characters that you might want to use fall outside the standard GSM character set and require more than one character to be sent. These non standard (unicode) characters allow the sending of symbols and emoticons but dramatically reduce the numbers of characters available, from 160 to just 70.
If we detect non-GSM characters, then the entire message is sent using the unicode standard and message length is reduced to 70.
The message length calculator incorporates a unicode detector which allows you to identify unicode characters in your messages. If you wish, you can then remove the unicode characters to restore message length to 160 characters.
Benefits of Using the SMS Length Calculator Tool
- Eliminate wastage and overspend by ensuring text message length limit is not exceeded and text messages are as compact as possible, without losing too much content or becoming confusing.
- The text message counter will identify any non- GSM characters that will cause message length to be reduced to 70 characters.
- Allows you to quickly experiment with multiple SMS message iterations to help you optimise message length and content.