Twilio · billing · fg-0162

One emoji or curly quote doubles the number of SMS segments you pay for

num_segments is 2 for a message well under 160 characters

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

A single character outside GSM-7, such as an emoji or a smart quote pasted from a word processor, switches the whole message to UCS-2, which fits 70 characters per segment, or 67 when split. Twilio bills per segment.

Fix

Normalize quotes and dashes before sending, avoid emoji in bulk sends, or turn on Smart Encoding in the Messaging Service. Check numSegments on the returned message.

Apply

const body = text.replace(/[\u2018\u2019]/g, "'").replace(/[\u201C\u201D]/g, '"');

Affects: SMS on all Twilio senders; segment sizes checked October 2026

Sources

https://www.twilio.com/docs/glossary/what-sms-character-limit

Have your agent know this before it fails

claude mcp add --transport http footgun https://getfootgun.com/api/mcp