SMS Delivery Problems
Troubleshoot text message delivery issues.
SMS Not Delivered
Check Customer Phone Number
Go to Customers
Find customer
Verify phone number:
Correct format: +1234567890
No spaces or dashes
Includes country code
Check Customer Verification
Customer must verify phone:
They enter phone number
Receive verification code
Enter code within 10 minutes
If not verified:
Customer won't receive SMS
Ask them to re-verify in account settings
Check Opt-Out Status
Customer may have opted out:
Go to Customers → [Customer Name]
Check Notification Preferences
See if "SMS Notifications: Disabled"
If opted out:
They replied STOP to a previous message
They can text START to resubscribe
Or update in account settings
SMS Delayed
Normal Delays
Typical: Delivered within seconds
Carrier Delays: Up to 5 minutes
Network Issues: Up to 30 minutes
What to Do
Wait: Give it 30 minutes
Check Twilio Status: status.twilio.com
Retry: Resend message if after 1 hour
SMS to Wrong Number
Why It Happens
Customer entered wrong number
Number changed
Typo during signup
How to Fix
Go to Customers → [Customer Name]
Click Edit
Update phone number
Save
Customer must re-verify new number
International SMS Issues
Common Problems
Not Delivered: Some countries block international SMS
Expensive: International rates higher
Formatting: Country code required
Supported Countries
We support SMS to:
United States (+1)
Canada (+1)
UK (+44)
Australia (+61)
100+ more countries
Unsupported Countries
Some countries don't allow SMS from US numbers:
China (limited)
Cuba
Iran
North Korea
Syria
Alternative: Use email for customers in these countries
Carrier-Specific Issues
AT&T
Sometimes delays messages during high traffic
Business messaging requires registration (we're registered)
T-Mobile
Strong spam filtering
Messages with links sometimes blocked
Verizon
Reliable delivery
Rare issues
Sprint/MVNO
Occasional delays
Same network as T-Mobile
Message Content Blocked
Why Messages Get Blocked
Spam Keywords: "Free", "Win", "Click here"
Too Many Links: Multiple URLs
Suspicious Patterns: All caps, excessive punctuation
Our Messages
All Preppable SMS are pre-approved templates:
Order confirmations
Pickup reminders
Delivery notifications
Rarely blocked because they're transactional (not marketing).
Character Encoding Issues
Problem Characters
Special characters may not display:
Emojis (⚠️ ✅ ❌)
Accented letters (é, ñ, ü)
Currency symbols (€, £, ¥)
Solutions
Standard characters work best
Use plain text
Avoid emojis in custom messages
Checking Message Status
Message Log
Go to Account → SMS Usage
Click Message Log
See status for each message:
Sent: Left our system
Delivered: Reached phone
Failed: Didn't deliver
Undelivered: Carrier issue
Failed Message Details
Click on failed message to see:
Error Code: Twilio error number
Error Message: Explanation
Common Fixes: Suggested solutions
Error Codes
21211: Invalid Phone Number
Cause: Phone number format wrong
Fix: Verify +1234567890 format
21214: Bad Destination
Cause: Number disconnected or invalid
Fix: Get updated number from customer
21408: Spam Detected
Cause: Carrier flagged as spam
Fix: Contact support for review
21610: Message Blocked
Cause: Customer opted out
Fix: Customer must text START to resubscribe
30007: Carrier Violation
Cause: Carrier-specific filter
Fix: Usually temporary, retry in 1 hour
Testing SMS Delivery
Send Test Message
Go to Customers
Find a test customer (or yourself)
Click Actions → Send Test SMS
Check if delivered
What to Test
Verify messages send
Check delivery speed
Ensure correct number
Confirm message format
Still Having Issues?
Contact Support
Email: [email protected] Include:
Customer name
Phone number
Message type (pickup reminder, confirmation, etc.)
Error message (if any)
Screenshot of message log
Contact Twilio
For deep technical issues:
Support: twilio.com/support
Status: status.twilio.com