Who This Is For / When to Use
Use this trigger if you want to:
Automatically respond to SMS delivery failures
Clean invalid or unreachable phone numbers
Handle opt-outs and DND scenarios
Notify your team when critical SMS errors occur
Improve SMS deliverability and compliance
What the Messaging Error – SMS Trigger Does
This trigger fires when an outgoing SMS fails and returns a recognized error code.
When triggered, Kyrios exposes the SMS error code so you can:
Filter workflows by specific failure reasons
Route contacts into different recovery paths
Prevent repeated failed sends
Supported SMS Error Codes
You can filter workflows using one or more of the following error codes:
30003 – Unreachable / Out of Service Number
30004 – Do Not Want SMS / DND Enabled
30005 – User Inactive / Number Does Not Exist
30006 – Landline / Unable to Receive SMS
30007 – Carrier Violation
30008 – Unknown Error
30011 – MMS Not Supported
30023 – Daily Message Cap Reached (US A2P)
30032 – Toll-Free Number Not Verified
30033 – A2P Campaign Suspended or Deleted
30034 – A2P Registration Pending
30037 – Outbound Messaging Disabled
30002 – Account Suspended
21211 – Invalid “To” Phone Number
21606 – Invalid “From” Phone Number
21610 – User Replied STOP (Opt-out)
21614 – “To” Number Is Not a Valid Mobile Number
21635 – “To” Number Is a Landline
21661 – “From” Number Is Not SMS-Capable
21408 – SMS Not Permitted to This Region
How to Set Up the Messaging Error – SMS Trigger
Step 1: Create or Open a Workflow
Go to Automations > Workflows.
Create a new workflow or edit an existing one.
Step 2: Add the Trigger
Click Add New Trigger.
Search for Messaging Error – SMS.
Select the trigger.
Step 3: Filter by Error Code
Use filters to target specific SMS failures.
Under Filters, select:
Error Code
Is any of
Choose one or more error codes
Click Save Trigger.
Recommended Actions by Error Type
Remove or Suppress Invalid Numbers
Use for:
30005User Inactive21211Invalid To Number21635Landline
Recommended actions:
Enable DND (SMS)
Remove phone number
Tag contact as
sms-invalid
Handle Opt-Outs Automatically
Use for:
30004Do Not Want SMS21610User Replied STOP
Recommended actions:
Enable DND for SMS
Add tag
sms-opted-out
Alert Your Team
Use for:
30007Carrier Violation30033A2P Campaign Suspended30037Outbound Messaging Disabled
Recommended actions:
Send internal notification
Pause related campaigns
Retry or Re-engage Later
Use for:
30003Out of Service30023Daily Cap Reached
Recommended actions:
Add delay
Tag contact for later retry
Switch to email follow-up
Example Workflow
Scenario: Automatically handle carrier violations.
Trigger: Messaging Error – SMS
Filter: Error Code =
30007 – Carrier ViolationActions:
Tag contact as
carrier-violationNotify admin team
Prevent future SMS sends
Best Practices
Always filter by specific error codes
Separate compliance errors from temporary delivery issues
Pair this trigger with DND workflows
Use tags to prevent repeated failed sends
Common Issues and Fixes
Workflow Does Not Trigger
Confirm the SMS actually failed
Verify the error code is selected in filters
Ensure the workflow is Published
Contacts Keep Receiving Failed SMS
Add DND or suppression actions
Remove invalid numbers immediately
Frequently Asked Questions
What triggers this workflow?
An outbound SMS returning a recognized error code.
Can I handle multiple errors in one workflow?
Yes. Select multiple error codes or use If/Else branches.
Does this work with Twilio and Native Phone?
Yes. The trigger supports both.
Can I retry SMS automatically?
Yes, using delays and conditional logic.
Does this replace compliance rules?
No. It helps you respond to failures but does not override carrier or regulatory requirements.