Who This Is For / When to Use
This article is for account owners and admins who:
Send SMS messages from Kyrios
Want to reduce SMS spend caused by invalid or landline numbers
Need automation triggers when a phone number fails validation
Use this feature when SMS deliverability and cost control are important.
What SMS and Phone Number Validation Does
SMS and Phone Number Validation uses Phone Number Lookup at the moment the first SMS is sent to a contact.
During validation, Kyrios:
Checks if the number exists
Detects landline numbers
Identifies SMS-incapable numbers (including some VOIP numbers)
Prevents SMS from being sent to numbers that fail validation
Important behavior:
Validation occurs only when an SMS is sent
Validation does not occur during contact creation or import
Each lookup has a small per-validation fee
How SMS Validation Is Activated
Step 1: Open Business Profile Settings
Navigate to:
Settings → Business Profile → General
Step 2: Enable SMS Validation
Locate and enable:
Validate phone numbers when first SMS is sent to a new contact
This setting activates Phone Number Lookup automatically at send time.
When Validation Happens (Critical Timing)
SMS validation happens:
When the first SMS is sent to a contact
SMS validation does not happen:
When creating a contact
When importing contacts
When editing a contact record
This ensures you only pay validation costs when an SMS attempt is made.
Using Workflows with Number Validation Errors
You can use Workflows to react when a phone number fails validation.
Common use cases include:
Internal notifications when SMS fails
Sending email instead of SMS
Tagging contacts with invalid phone numbers
Cleaning lists before future SMS campaigns
Step-by-Step: Creating a Number Validation Workflow Trigger
Step 1: Open the Workflows List
Navigate to:
Automations → Workflows
Create a new workflow or edit an existing one.
Step 2: Add a Workflow Trigger
Inside the workflow builder:
Click Add New Trigger
Select Number Validation from the Events list
Step 3: Configure Number Validation Filters
Choose how the trigger should fire based on validation results.
Available filter options include:
Not Valid (e.g. invalid or malformed numbers – error 21211)
SMS Incapable (e.g. landlines or unsupported numbers – error 30006)
Select one or both filters depending on your use case.
Step 4: Add Workflow Actions
After the trigger is set, add any actions you want, such as:
Send an internal notification
Send an email to the contact
Apply a tag (e.g.
Invalid Phone Number)Update a custom field
Save and publish the workflow to activate it.
Common Issues and Fixes
SMS Still Sending to Invalid Numbers
Confirm SMS Validation is enabled in Business Profile settings
Ensure the SMS being sent is the first SMS to that contact
Workflow Not Triggering
Verify the trigger type is Number Validation
Confirm the correct filter (Not Valid or SMS Incapable) is selected
Make sure the workflow is Published, not Draft
Unexpected Validation Charges
Charges only occur when an SMS send attempt is made
Contact imports and edits do not trigger validation fees
FAQ
What is SMS validation, and how does it work?
SMS validation checks phone numbers at the moment an SMS is sent. Kyrios uses Phone Number Lookup to identify invalid numbers, landlines, and SMS-incapable numbers and blocks SMS delivery to those numbers.
How do I activate SMS validation in my account?
Go to Settings → Business Profile → General, enable Validate phone numbers when first SMS is sent to a new contact, and save your changes.
Are there costs associated with SMS validation?
Yes. Each phone number lookup has a small per-validation fee. This cost helps prevent higher SMS delivery and carrier rejection costs.
When is SMS validation performed?
Validation is performed when the first SMS is sent to a contact. It does not occur during contact creation or contact import.
Can I automate actions when a phone number is invalid?
Yes. You can create workflows using the Number Validation trigger to send notifications, apply tags, or route communication through email instead of SMS.
Does SMS validation work for short codes or toll-free numbers?
SMS validation checks the recipient’s phone number, not your sending number. It accurately detects whether the recipient is using a mobile phone, VOIP number, or landline.