AVS Mismatch: What It Means and What to Do
An AVS mismatch is a warning, not proof of fraud. Here is what the check compared, why good orders fail it, and what to do next.
The order looks normal. Then the payment result says the billing address check failed. Before you cancel, learn what the check actually compared.
What AVS is and what a mismatch means
The Address Verification System is a service that checks if a billing address matches the address of a credit card cardholder. It is a common fraud-prevention measure for card not present transactions, such as online payments or Mail Order/Telephone Order payments. Every sale you make online falls under that label.
AVS checks the billing address, not the shipping address. Where the box goes is a different matter, and no check answers it for you. A mismatch means the address the customer typed did not match what the card issuer has on file.
Why mismatches happen on legitimate payments
AVS checks can fail for legitimate payments. One buyer types a unit number as 4B, another as Apt 4-B, and both mean the same door. The card works and the buyer is who they say they are.
If the customer seems genuine but the check still failed, see avs mismatch on a legitimate order. A mismatch is one signal, not a verdict.
Partial matches and response codes
The result is not always a plain yes or no. Some results are partial. Adyen's docs say AVS result 15 means the postal codes match but the street address was not verified because of incompatible formats. That can happen when the customer writes the address a little differently than the bank does.
Result 22 means the card member's name matches, but the billing address and billing postal code do not. It is still not proof of fraud.
Some results mean nothing at all. AVS response code 3 means AVS is unavailable and applies to Discover. The check did not run, so there is nothing to compare.
For the full list, see avs response codes.
What to do when you see one
Using the AVS response, you can choose to accept a transaction, make an exception, or cancel it. You have those three options, and the pick is yours to make.
Weigh the result against the rest of the order details. Based on the AVS response, you can decide to accept, make an exception, or cancel a transaction.
Choose one approach and apply it to every similar order after that. Write the rule down so your staff follows it too.
How AVS works alongside the CVC check
AVS is not the only check on the order. The CVC is the three- or four-digit number printed directly on a card. A failed CVC or postal code check can indicate the payment is fraudulent. Can, not does.
The two checks look at different things. AVS compares an address. The CVC check looks at the three- or four-digit number printed on the card. If the cvv check failed as well, the order looks worse than an AVS mismatch by itself.
Collect the CVC, postal code, and billing address for every payment, so both checks always have something to compare.
Setting rules in your payment tools
You do not have to judge every order by hand. Adyen's documentation says that when the AVS check results in a mismatch, you can trigger a risk rule. Radar allows you to block payments that fail the card issuer verification by enabling a rule through the Dashboard. Shopify's guide says fraud indicators can include AVS checks and the correct CVV code.
Using AVS is not mandatory for you as a merchant. You can make an exception when a good customer fails it. Most cards issued in the United States, Canada, and the United Kingdom support street address verification. AVS also works with Visa, Mastercard, Discover or American Express cards. Credit card issuers in the United States, Canada, the United Kingdom, and Europe for Visa must support AVS verification requests.
These rules are one part of card not present fraud prevention. No rule catches every bad order, and no rule should cancel every good one. A mismatch tells you to look closer. It does not tell you the customer is a thief.