Phone validation is becoming a standard fraud prevention tool for e-commerce businesses. Chargebacks cost online merchants an estimated 1–2% of revenue, and friendly fraud — where the actual cardholder disputes a legitimate charge — accounts for a large share. By validating the phone number associated with an order, merchants gain an additional signal to assess risk before fulfilling and shipping.
How Phone Data Helps Detect Fraudulent Orders
A fraudulent order often has subtle inconsistencies that phone validation can surface:
- VoIP number on a high-value order — Fraudsters use disposable VoIP numbers to avoid traceability. A $500 order placed with a Google Voice number and a shipping address that doesn’t match the billing address is a red flag.
- Disconnected or suspended number — A phone number that is no longer active suggests the contact data may be stolen or fabricated.
- Geographic mismatch — The phone number’s area code or GeoIP data shows a different state or country than the billing or shipping address.
- Landline on a mobile-only flow — If the customer claims to have received an SMS confirmation but the number is a landline, something doesn’t add up.
These signals don’t prove fraud on their own, but combined with other order data, they help you make better risk decisions.
Integrating Phone Validation Into Your Order Flow
At Checkout
Validate the phone number when the customer enters it during checkout. Use the CheckThatPhone API to check line type, deliverability, and carrier data in real time. If the number is invalid or high-risk, prompt the customer to re-enter or flag the order for manual review.
In Your Fraud Scoring System
Feed phone validation results into your existing fraud scoring model. Add rules like:
- VoIP number + new account + high order value = elevated risk
- Disconnected number + express shipping = flag for review
- Phone GeoIP mismatch with billing address = additional verification required
Post-Order Verification
For flagged orders, use the validated phone number to send an SMS verification code before shipping. This confirms the customer has access to the number they provided and adds a layer of identity verification.
Reducing Chargebacks
Chargebacks happen when a cardholder disputes a transaction. Phone validation reduces chargeback rates in several ways:
- Blocking fraudulent orders before fulfillment prevents the chargeback from ever occurring
- SMS verification creates a paper trail proving the customer confirmed the order
- Better customer data means fewer order issues that lead to legitimate disputes (wrong address, unreachable customer)
For merchants in high-risk categories — supplements, electronics, subscription boxes — every percentage point reduction in chargebacks translates directly to revenue.
What the API Returns
CheckThatPhone returns the following fields relevant to e-commerce fraud detection:
- Line type (mobile, VoIP, landline)
- Carrier name and subtype
- Deliverability status
- Deactivation and porting history
- GeoIP location and timezone
See the complete API response format for integration details.
Getting Started
Phone validation adds a powerful signal to your e-commerce fraud prevention stack. By checking phone numbers at checkout, you catch fraudulent orders earlier, reduce chargebacks, and ship with more confidence. Read the API documentation to integrate phone validation into your order flow, or explore pricing plans to get started.