AVS
Also known as: Address Verification Service
A fraud check that matches the billing address entered against the card issuer's records.
AVS (Address Verification Service) compares the numeric parts of the billing address a customer enters with what the issuing bank has on file. A mismatch is a fraud signal you can use to flag or decline card-not-present transactions. It's commonly paired with a CVV check.
How it works
AVS never declines anything. Your gateway posts the numeric street number and ZIP the shopper typed alongside the authorization request, the issuer compares them with its own records, and a single letter comes back with the approval. Y means the street number and the ZIP both matched. Z means the ZIP matched and the street number did not, A is the other way round, and N means neither matched. U or S tell you the issuer did not check. Only the digits are compared, so street names and spelling never come into it.
The approval or decline is the issuer's own call, made on funds and its fraud model. The letter only tells you how well the address fitted. The rule is yours to write. In your gateway you decide to accept Y and Z, send A to review, reject N, or whatever balance suits what you sell. Too tight and you turn away customers who typed an old address. Too loose and you carry fraud you could have stopped.
A rejection is not free. The issuer had already approved the authorization before your rule voided it, so the customer can see a pending hold on their card for a few days, and some processors bill an authorization fee whether or not the sale completes. Coverage is the other problem. Outside the US, Canada, and the UK, plenty of issuers simply report that no check was performed, so a rule written to catch fraud quietly starts blocking good international orders instead.
Worked example
A customer at 42 Oakfield Avenue, ZIP 90210, types '42 Oakfeild Ave' and the same ZIP 90210. AVS returns Y. The misspelling is irrelevant, because the only things compared are the digits 42 and 90210. A second order comes in with the same street number but ZIP 90211, which returns A. Reject anything other than Y and that sale is voided, most likely on a customer who moved house and never told their bank.
Frequently asked questions
- Does an AVS mismatch mean the card is stolen?
- Most mismatches are honest. A customer moved, the card is registered to a partner's address, or the order is a gift billed to one address and shipped to another. Treat the code as one input among several rather than a verdict: read it next to the CVV result, the order value, and what you know of the customer, and send the borderline ones to manual review instead of declining them.
- Does passing AVS protect me from a chargeback?
- AVS carries no liability protection, unlike a successful 3D Secure authentication. A matching address is useful evidence when you fight a dispute, but the issuer still decides who wins. AVS earns its keep by stopping bad orders before they settle rather than by winning disputes afterwards, so treat it as a screening tool and not a shield.
- Does AVS work for international customers?
- Rarely. Mainly US, Canadian, and UK issuers support it, and most other banks return a code meaning the check was not performed. Block those responses and you reject nearly every overseas order, so set your rules by issuer country. Strict AVS at home, and for international traffic lean on CVV, 3D Secure, and device or velocity checks.