What is Unicode in SMS messaging

Unicode is a key concept in SMS messaging, especially for businesses communicating across markets and languages. It defines how characters are encoded and determines which symbols, letters and emojis can be used in a message.

Understanding Unicode helps you control message length, cost and delivery while ensuring your content appears exactly as intended on customer devices.

What Unicode means in SMS messaging

Unicode is a character encoding standard that supports a very large set of characters. In SMS messaging, Unicode allows content beyond the basic Latin alphabet used in standard GSM encoding.

Unicode makes it possible to send SMS messages that include:

• Accented characters such as å é ñ

• Non Latin alphabets such as Arabic Cyrillic or Chinese

• Emojis and symbols

• Special punctuation and formatting characters

If an SMS contains even one character that is not supported by GSM encoding, the entire message is sent using Unicode.

Unicode vs GSM encoding in SMS

SMS messages use either GSM encoding or Unicode encoding. The difference between the two affects how many characters fit into a single message.

GSM encoding supports up to 160 characters and works well for basic English text and some Western European characters.

Unicode encoding supports a much wider character set but reduces the maximum length of each SMS.

This difference becomes important when messages are longer and split into multiple parts.

How Unicode affects SMS character limits

Unicode changes how many characters fit into one SMS.

• GSM encoded SMS supports up to 160 characters
  Unicode SMS supports up to 70 characters

• When a message is longer and split into multiple parts:

• GSM multipart SMS uses 153 characters per part

• Unicode multipart SMS uses 67 characters per part

it is useful to check how your content is encoded before sending. You can test your message length and encoding using the LINK Mobility SMS length calculator.

Examples of Unicode in SMS messaging

Unicode is often triggered by characters that appear harmless or are added automatically by keyboards and text editors.

When Unicode is required in SMS messaging

Unicode is required whenever your message includes characters that GSM encoding cannot support. This is common in multilingual communication and customer facing messaging.

Unicode is often triggered by:

• Emojis in promotional messages

• Accented characters in local languages

• Smart punctuation copied from documents

• Currency symbols

• Non Latin alphabets

Once Unicode is triggered, the full message uses Unicode encoding, even if the rest of the text is GSM compatible.

Why Unicode affects SMS performance

Unicode directly affects both cost and message structure. Messages that exceed character limits are split into multiple SMS parts, increasing delivery cost.

Unicode also affects readability and brand perception. Removing local characters or symbols to avoid Unicode can make messages feel unnatural or unclear for customers.

The goal is not to avoid Unicode but to understand when it is needed and how it affects message length.

How to manage Unicode SMS effectively

Managing Unicode SMS requires awareness and the right tooling.

Best practices include:

• Checking character encoding before sending

• Avoiding unnecessary emojis in operational messages

• Adjusting copy by language and market

• Using messaging platforms that show encoding and character count

• Testing message length before large scale sends

With proper visibility, Unicode becomes predictable and easy to manage.

Unicode and global SMS communication

Unicode plays a central role in global SMS communication. It allows businesses to communicate in native languages and use symbols that customers recognise and trust.

For international brands, Unicode ensures consistency across regions while supporting local relevance.

LINK Mobility supports Unicode SMS across all major messaging channels, enabling accurate and compliant communication at global scale. With full visibility into character encoding and message length, businesses stay in control of both experience and cost.