SMS Character Limit

To help you optimize your communication strategy and avoid unexpected SMS costs, it’s important to understand how SMS character encoding and message splitting work. Let's explore it here!

Standard SMS Character Limit

A standard SMS message supports up to 160 characters using the GSM-7 character set (including basic Latin letters, numbers, and common symbols).

If your message contains any Unicode character (such as emojis or non-Latin letters), it will be encoded using the UCS-2 character set, and the limit per message drops to 70 characters.

What happens when a message exceeds the limit?

When an SMS exceeds the character limit:

• It is split into multiple parts before being sent.

• Each part is billed as an individual SMS.

Encoding	Message Limit	SMS Part Text Limit
GSM-7	160 characters	153 characters
UCS-2	70 characters	67 characters

For example:

• A GSM-7 message with 161 characters will be sent in 2 parts (153 + 8 characters).

• A UCS-2 message with 150 characters will be sent in 3 parts (67 + 67 + 16).

Use the following tool to calculate how many parts your message will generate:

Messaging Segment Calculatortwiliodeved.github.io

Be cautious with Special Characters

Even one Unicode character (like an emoji or changes from " to ') will trigger UCS-2 encoding and reduce the character limit per SMS.

If your text editor changes " to “ — a 'curly' quote mark—you will have a UCS-2 character in your message, reducing the character limit from 160 to 70.

Common mistakes that cause UCS-2 encoding:

• Emojis (😊, 🎉, etc.)

• Smart quotes: “ ” instead of ' '

• Special dashes or accented characters not in GSM-7

Best Practices to Reduce SMS Cost

• Use plain text and GSM-7 compatible characters when possible.

• Keep messages concise.

• If using long messages, try to stay below 153 characters per part.

• Always test your message content before sending a campaign.

For more information about special characters, please visit the following article:

GSM 03.38Wikipedia