SMS Messages and Segments - What are they?

In this guide, we will cover SMS messages and segments to help you understand how they work and how to avoid additional charges from mobile carriers. Further, we'll explore how the length and character type of your message impact the segmentation. Mosio has been designed to help clients maximize their messaging content and includes counters to help you. More on that below.

What is an SMS Segment?

• SMS messages are made up of character batches called segments. Each segment is limited to 160 simple characters in order to fit network limitations.  So what might seem like a single message to you could, in fact, be made up of several segments.
• The length of a text message depends on two things:
  • The length of your message, and
  • The type of characters used to create your message
• Length of SMS segments, broken down:

• 1-160 character(s) = 1 SMS segment
• Over 160 characters causes messages to be concatenated into one large message, and this reduces the length available to 153 characters:
  • 161-306 characters = 2 SMS segments
• After you've reached 306 characters, every 153 characters would count as an additional SMS segment (ie 307-460 characters = 3 SMS segments)

• Character types can affect the segment count
  • Using characters other than letters and numbers can cause carriers to use a different type of encoding (UCS-2), doubling the segments needed to send it (halving the number of characters per segment).
    • A single UCS-2 segment is up to 70 characters
    • Multiple UCS-2 segments concatenate as mentioned above, reducing the limit to 67 characters for each segment
  • These characters include emojis, diacritical marks, and letters in non-English languages (outside of GSM-7)
  • Mosio changes some characters, like stylized quotes, apostrophes, and ellipses into standard formats to avoid encoding changes, saving you money.

How to avoid additional charges by mobile carriers?

• Carriers bill 160 regular characters (letters, numbers and symbols above numbers on your keyboard) as 1 message segment. Any messages that exceed 160 characters will be charged for additional SMS segments.,
• Limiting your message segment to a maximum of 160 basic characters is highly recommended.
• Use standard GSM-7 characters (regular characters) in your messages.
• In general, avoid special characters like emojis
• Shorten your word counts by using “4” instead of “for”, or “2” instead of “to”.
• If your message exceeds 160 basic text characters, you have the option to send as 1 single long message or multiple messages.  Please note that the delivery order of multiple messages can’t be guaranteed.

How Mosio Helps

Mosio has a built-in character, message and segment counter to help you better create and maximize the effectiveness of your messaging content.