Summary: We’ve identified a scenario where SMS messages may generate higher-than-expected segment counts when emojis or certain special characters are used. This behavior is not unique to Denticon. This follows standard SMS carrier encoding rules used across the telecommunications industry.
What Happens
SMS messages are sent using one of two encoding types:
GSM Encoding (Standard)
- Supports up to 160 characters per segment
- Used for plain text messages with standard characters
UCS-2 Encoding (Triggered by Emojis/Special Characters)
- Supports approximately 70 characters per segment
- Automatically used when:
- Emojis are included
- Unsupported or special characters are present
When a message switches to UCS-2 encoding, the same text may require multiple SMS segments, increasing cost.
Examples
Standard GSM Message
- 160 characters = 1 segment
- May split into 2 segments depending on length
Spring Special at #OFFICE_NAME#! Get a Full Exam & X‑Rays for just $89.
Now accepting new patients! Use your tax refund to invest in a healthy smile.
Call today to schedule your checkup #OFFICE_PHONE1# or schedule online: #URL_APPOINTNOW#
Message with Emoji or Special Characters
- Same message length may become 3+ segments
- Example converted into 5 segments
Spring Special at #OFFICE_NAME#! 🌸 Get a Full Exam & X‑Rays for just $89.
Now accepting new patients! Use your tax refund to invest in a healthy smile.
Call today to schedule your checkup #OFFICE_PHONE1# or schedule online: #URL_APPOINTNOW#
The Denticon Patient Communication template editor:
- Is a plain text editor
- Does not include emoji tools
However, users can still:
- Copy and paste content from other apps
- Insert emojis or special characters unknowingly
When this happens:
- The message automatically switches to UCS-2 encoding
- Segment limits drop from 160 → ~70 characters
- Total segment count (and cost) increases
Best Practices
To minimize SMS segment usage and costs:
- Avoid emojis in SMS templates
- Avoid special or non-standard characters
- Keep messages concise
- Use standard GSM-compatible text whenever possible
Why This Matters
Using GSM-compatible text helps:
- Reduce SMS costs
- Prevent unexpected overages
- Improve message efficiency
- Ensure predictable billing
Additional Notes
- SMS billing is based on total segments sent, not the message as shown in the editor
- Segment calculations follow industry-standard carrier rules
- This behavior applies across all SMS platforms, including Twilio
Any additional questions, please refer to your Account Management team or reach out to support@planetdds.com