Message Segments, Text Encoding, and Your Dialer Billing Charges

If your Dialer text usage charge was higher than expected, message segments are almost always the reason. This article explains what a segment is, why some texts cost more than others, and how to keep your usage low without changing what you say to clients.

Table of Contents

1. Before You Begin
2. What It Is
3. Why It Matters for Your Business
4. How Segments Are Calculated
5. Step-by-Step: Checking Your Usage and Your Messages
6. Best Practices
7. Troubleshooting Common Issues
8. FAQs

Before You Begin

• Your Sierra Dialer must be activated to send texts. If you don't see texting options in your account, see Getting Started with Your Sierra Dialer (Agent Guide).
• This article explains what drives your segment count and usage charge. For a walkthrough of the Dialer Billing Detail page itself, including package allotments and overage pricing, see Understanding Your Dialer Billing Details.

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What It Is

A standard text message caps out at 160 characters. Once a message runs longer than that, it gets split into pieces called segments, sent separately, and reassembled on the recipient's phone. Your Dialer plan bills by segment, not by message, so a single long text can cost the same as sending several short ones.

The character set used to encode a message decides how many characters fit in each segment, and that's the piece most agents never see. Two encodings apply:

The switch from GSM-7 to UCS-2 happens the instant a single unsupported character appears anywhere in the message. Common triggers include:

• Emoji
• Curly or "smart" quotes (often inserted automatically by Word, Outlook, or iOS)
• Symbols like ®, ™, or ©
• Accented characters, such as café or José
• Em dashes, bullet characters, or ellipses carried over from pasted text
• Non-Latin scripts

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Why It Matters for Your Business

Because UCS-2 cuts the per-segment limit by more than half, one small formatting choice can multiply your segment count and your usage charge. A recent real-world example makes this clear: a 1,466-character lead follow-up text sent as 22 segments, driven entirely by a single ® symbol after "REALTOR" in the agent's signature. Removing that one character alone brought the same message down to 10 segments, a 55% reduction, without changing a single word of the actual message.

The pattern holds at any length. The longer a message runs, the more each hidden character costs, so the fix that saves one or two segments on a short text can save seven or more on a long one.

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How Segments Are Calculated

Not every text message follows segment-based billing. Sierra's Dialer supports three message types, and each is billed differently:

If your usage charge is coming from Group MMS rather than SMS, the segment rules above won't explain it, since a single group text to 10 people is billed as 10 messages.

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Step-by-Step: Checking Your Usage and Your Messages

You don't need to guess which of your messages are running up segments. Two tools make it visible before and after you send.

Check your account's segment totals

1. Go to the Gear Icon in your Sierra Client Admin Area (CAA).
2. Select Dialer Billing Details.
   
3. Review the estimated segment counts, MMS and Group Text totals, and any additional usage charge for your selected date range.

Numbers shown here are estimates based on activity timing. Your finalized, reconciled totals appear on your monthly invoice. For a full breakdown of what each column means, see Understanding Your Dialer Billing Details.

Check a message before you send it

1. Copy the message you plan to send.
2. Paste it into the Twilio Messaging Segment Calculator.
3. Review the character count, encoding, and segment total shown.

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Best Practices

• Run saved scripts and drip campaigns through the calculator before sending. A template that reads clean can quietly pick up a curly quote or symbol during an edit, and you won't see it unless you check.
• Paste signature blocks and templates as plain text. Word, Outlook, and iOS often convert straight quotes to curly ones automatically, and ®, ™, and © marks are common in signature blocks. Use Ctrl or Cmd + Shift + V when pasting into Sierra to strip that formatting before it costs you segments.
• Keep prospecting and mass texts under 160 characters where possible. Short, plain-text messages stay in GSM-7 and avoid the segment penalty entirely.
• Skip emojis in scripted or bulk texts. One emoji converts the entire message to UCS-2, which is fine occasionally but costly at volume. For guidance on using emojis intentionally, see How to Add Emojis to Your Text Messages.
• Re-check templates periodically, not just when you first build them. A script edited six months after launch can pick up a stray character without anyone noticing until the bill reflects it.

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Troubleshooting Common Issues

• My segment count seems high, but my message looks like plain text.
  Paste the message into the Twilio Messaging Segment Calculator to check for hidden characters. Curly quotes and pasted symbols are invisible in most text editors but still trigger UCS-2 encoding.

• My usage charge is coming from MMS or Group Text, not SMS.
  Segment rules don't apply to MMS or Group MMS. Review the MMS / Group Text columns on your Dialer Billing Details page separately, since these are billed per message, not per segment.

• The numbers on my Dialer Billing Details page don't match my invoice.
  This is expected. The CAA shows an estimate based on activity timing; your invoice shows the finalized, reconciled totals. See Understanding Your Dialer Billing Details for more on how reconciliation works.

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FAQs

• Does a longer message always cost more?
  Not necessarily on its own. A long message in GSM-7 encoding can still cost less than a short message that switched to UCS-2 because of a single special character.

• Can I tell which encoding a message will use before sending it?
  Yes. Paste it into the Twilio Messaging Segment Calculator to see the encoding, character count, and segment total before it reaches a client.

• Does this affect email or voicemail drops?
  No. Segment-based billing applies only to SMS text messages. Email and voicemail drops are billed differently.

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