When sending SMS messages through bLoyal Engagement, the characters you use determine how your message is encoded — and encoding directly affects how many segments your message uses. More segments mean higher sending costs. This article explains the difference between the two encoding types, which characters to avoid, and how to write messages that stay efficient.
Quick summary: Keep your messages in GSM-7 encoding to maximize character limits and minimize cost. A single non-GSM-7 character — like an emoji or a curly quote — can cut your per-segment capacity by more than half.
Understanding the Two Encoding Types
SMS supports two character encodings. The one used for your message is determined automatically based on the characters it contains.
| Encoding | Triggered by | Single message limit | Multipart segment limit |
|---|---|---|---|
| GSM-7 | Standard Latin characters only | 160 characters | 153 characters per segment |
| UCS-2 | Any character outside GSM-7 (emojis, smart quotes, accented letters, etc.) | 70 characters | 67 characters per segment |
Why this mattersA 180-character plain English message uses2 GSM-7 segments. Add a single emoji and that same message jumps to3 UCS-2 segments— a 50% cost increase from one character.
Characters That Are Safe to Use (GSM-7)
The following characters are all GSM-7 compatible and will not affect your encoding:
These characters are also GSM-7 but count as 2 characters each (extended GSM-7). Use sparingly:
Characters That Force UCS-2 Encoding
Any of the following will immediately switch your entire message to UCS-2, dropping your segment capacity from 153 to 67 characters:
| Character | Description | Safe Alternative |
|---|---|---|
| " " | Curly/smart double quotes | "straight quotes" |
| ' ' | Curly/smart single quotes or apostrophes | 'straight apostrophe' |
| — | Em dash |
- (regular hyphen) |
| – | En dash |
- (regular hyphen) |
| … | Ellipsis character |
... (three periods) |
| • | Bullet point |
- or *
|
| 🎉 😊 ✅ | Any emoji | Plain text alternative |
| é ñ ü à | Accented/diacritical letters | Unaccented equivalent (e, n, u, a) |
| Non-Latin scripts | Arabic, Chinese, Korean, etc. | Separate campaign in target language with UCS-2 budgeted for |
The #1 Cause of Accidental UCS-2: Copy-Paste from Word or Email
Most common mistake: Copying message text from Microsoft Word, Google Docs, Outlook, or Apple Notes almost always introduces smart/curly quotes and em dashes automatically — even if you typed straight characters. These are invisible in most editors but will silently switch your message to UCS-2.
How to avoid it:
- Write messages directly in bLoyal Engagement (preferred) or a plain text editor (Notepad on Windows, TextEdit in plain text mode on Mac as a secondary option only) rather than copying from Word or email.
- If you must copy from Word, paste into Notepad first to strip formatting, then copy again into bLoyal Engagement. This, however, does not guarantee that you will not introduce unintended characters that will silently introduce a UCS-2
- Turn off AutoCorrect smart quotes in Word: File → Options → Proofing → AutoCorrect Options → AutoFormat As You Type → uncheck "Replace straight quotes with smart quotes."
- Use a character checker before sending — tools like this free GitHub message segment calculator will tell you your encoding and segment count in real time.
How to Calculate Segments for Your Message
- Determine your encoding (GSM-7 or UCS-2) based on the characters used.
- Count your total characters including spaces and punctuation.
- Apply the correct thresholds:
| Encoding | If ≤ limit | If > limit | Segments formula |
|---|---|---|---|
| GSM-7 | 160 chars → 1 segment | Split at 153 chars | ceil(chars ÷ 153) |
| UCS-2 | 70 chars → 1 segment | Split at 67 chars | ceil(chars ÷ 67) |
Quick Reference Checklist Before Sending
- ✅ Written in plain text — not pasted from Word, Outlook, or Google Docs
- ✅ No curly/smart quotes — using straight
'and"only - ✅ No em dashes (
—) — using hyphens (-) instead - ✅ No ellipsis character (
…) — using three periods (...) instead - ✅ No emojis
- ✅ No bullet points (
•) — using-or*instead - ✅ Character count verified using a segment calculator
- ✅ Opt-out language included (
Reply STOP to opt out)
Need Help?
If you're unsure whether your message is GSM-7 or need help troubleshooting unexpected segment counts, contact bLoyal Support or use the in-app chat. You can also paste your message into messagesegmentcalculator.com for an instant encoding and segment breakdown.
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