SMS Messages and Segments - What are they?

Note: Any outbound text message sent by Mosio counts against your message credits. These include (but are not limited to) survey questions, auto-responders, replies to TextChat, SMS notifications, appointment reminders, storyline messages, etc. 

At a Glance

Long texts are sent as multiple segments, and you are billed on these segments. Keep your texts short!

• Text messages are typically 160 characters, max.
• Remove emojis from longer messages! 
  → Max is reduced to 70 characters if you include emojis, or non-Latin characters (like Chinese, Hindi, Japanese, etc)
• Carriers support concatenated texts, which can be much longer. However, these long texts are broken up into individual texts (known as segments) and sent over the network, incurring a cost per segment. 
• Use Mosio's Character Counter to view your segment count in order to keep your costs down.

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.

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.

A Note About MMS / Photos

Segment credits also cover photo messages (MMS). Each MMS sent or received counts as 5 segment credits, since photo messages are heavier than standard SMS and carriers price them accordingly. If your project uses photos for participant check-ins, intervention content, or visual instructions, just factor the 5-credit rate into your usage planning so there are no surprises. More info about MMS.

A Note About Voice Services (Voice Forwarding and Click to Call)

Mosio's voice features also draw from your segment credits. Voice Forwarding, which routes inbound calls placed to your Mosio number out to a study team line, is 1 segment credit per minute. Click to Call, which lets you place outbound calls from your dashboard to a participant, is 3 segment credits per minute. Both are optional. Voice Forwarding can be enabled in Tools > Project Settings, and Click to Call (Basic and Plus Plans) can be activated by emailing Support or opening up a ticket. More info about Voice Services.

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”.