Who This Is For / When to Use
This trigger is for users who send SMS or make calls using Twilio and want to automatically handle phone number validation failures.
Use this trigger when you want to:
Detect invalid or SMS-incapable phone numbers
Prevent repeated failed send attempts
Notify internal teams of contact data issues
Automatically request updated contact information
What the Twilio Validation Error Trigger Does
The Twilio Validation Error trigger runs before an SMS or call is sent.
When Twilio returns a validation error:
The affected contact is immediately added to the workflow
The workflow can run internal or contact-facing actions
No SMS or call is sent to the invalid number
This trigger relies on Twilio Lookup results and only fires when a validation failure occurs.
Requirements Before Using This Trigger
The following setting must be enabled for this trigger to work:
Number Validation must be enabled in Agency Twilio Settings
If Number Validation is disabled, the trigger will never fire.
Step 1: Create or Open a Workflow
Go to Automations > Workflows
Click Create Workflow, or open an existing workflow
Ensure the workflow is in Draft mode before editing triggers
This step prepares the workflow container where the trigger will be added.
Step 2: Add the Twilio Validation Error Trigger
Click Add New Workflow Trigger
Open the Contact Actions section
Select Twilio Validation Error
You can also find it using the search bar
Once selected, the Trigger Setup panel opens automatically.
Step 3: Configure Trigger Settings
Each configuration option below works independently and can be quoted on its own.
Workflow Trigger Name (Optional)
This field changes only the display name inside the workflow builder
It does not affect trigger behavior or execution
Use this to clearly label workflows for internal reference.
Error Filter
Use the Error is filter to define which validation errors trigger the workflow.
Available options:
SMS Incapable – The phone number cannot receive SMS
Not Valid – The phone number fails Twilio validation entirely
Both – Triggers on either error type
If no error is selected, the trigger will not fire.
Custom Field Filters (Optional)
You can further restrict which contacts enter the workflow.
Filters are based on existing Custom Fields
Custom Fields must already exist in the account
Only contacts matching the selected values will enter the workflow
This is commonly used to limit actions by region, pipeline stage, or contact type.
Save the Trigger
Click Save Trigger in the bottom-right corner of the Trigger Setup panel
The trigger is now active inside the workflow.
Step 4: Add Workflow Actions
After the trigger fires, you can add any workflow actions, including:
Internal notifications
Tagging the contact
Updating contact fields
Creating tasks
Sending emails (not SMS)
Assigning users
Actions run in sequence for every contact added by the trigger.
Important:
A workflow can be published with or without actions. If no actions are added, the workflow will still log trigger events.
Step 5: Save, Test, and Publish the Workflow
Click Save in the top-right corner
Toggle Publish to enable the workflow
Click Test Workflow to validate behavior before going live
Testing confirms the workflow runs correctly when a validation error occurs.
Common Issues and Fixes
The workflow never triggers
Confirm Number Validation is enabled in Agency Twilio Settings
Ensure the Error filter is set to SMS Incapable, Not Valid, or Both
Contacts are not added to the workflow
Verify the phone number actually fails Twilio validation
Check that Custom Field filters are not excluding the contact
SMS actions do not send
SMS actions should not be used after this trigger
The trigger fires because the number cannot receive SMS
Use email or internal actions instead.
FAQ
What causes the Twilio Validation Error trigger to fire?
The trigger fires when Twilio returns a validation failure before an SMS or call is sent.
Does this trigger run after an SMS is sent?
No. It runs before sending, based on Twilio Lookup validation results.
Can I send SMS messages inside this workflow?
No. The trigger fires specifically because the number cannot receive SMS or is invalid.
Can I filter which validation errors trigger the workflow?
Yes. You can choose SMS Incapable, Not Valid, or both using the Error filter.
Is this trigger contact-specific?
Yes. The contact whose phone number caused the validation error is added to the workflow.