Address verification service (AVS) response codes explained

When customers make a payment, their billing address is often checked against the one on file with the card issuer. This step, called address verification, helps confirm the cardholder’s identity and reduce fraud. The result of that check comes back as an AVS response code. Knowing what those codes mean is important for merchants, because they affect whether a payment is approved or declined.

What is address verification service?

Address verification service (AVS) is a security feature used to validate the billing address provided by a cardholder during a transaction. It compares the numeric portions of the billing address submitted — typically the street number and zip code — against the address information held by the issuing bank. This verification step is widely used in card-not-present transactions, such as e-commerce purchases, as part of broader fraud prevention strategies.

When a transaction is initiated, the AVS check is triggered automatically, requiring no extra steps from the cardholder. The result is returned as an AVS response code, which the merchant can then interpret to determine whether to approve, decline, or flag the transaction for review.

What are AVS codes?

AVS codes are alphanumeric indicators that provide the outcome of the AVS check. These codes tell you whether the billing address provided by the customer matches the one on file with the card issuer. If the code matches both the zip code and street number, the transaction is typically considered lower risk. A partial match or mismatch can trigger additional security protocols.

AVS response codes matter because they add another layer of intelligence to fraud prevention. While not foolproof, they help filter suspicious transactions, especially in card-not-present environments. AVS codes are most commonly used in countries like the US, Canada, and the UK, where the address verification system is well-established across major card networks such as Visa, Mastercard, and American Express.

How AVS codes are determined

When a customer submits payment, an AVS check runs in the background. The issuing bank reviews the numeric part of the billing address against its records. Based on this comparison, the bank generates a response. If the address data aligns fully, the result is a full match. If only part of it matches, such as the zip code but not the street number, it’s marked as a partial match. A total mismatch leads to a different response code.

This process happens in real time and doesn’t require any manual intervention. The code returned can influence whether the transaction is approved automatically, routed for manual review, or declined outright depending on the merchant’s fraud settings.

Classification of AVS codes

AVS codes can vary by card network and issuing country. AVS codes are fairly consistent within the US and Canada. International AVS support is less common and can be inconsistent. Some banks outside North America may not return AVS responses at all.

Each card network has its own set of AVS codes:

• Visa and Mastercard both support a standardised AVS code system in supported markets.
• American Express has a slightly different format but serves the same purpose.

While the meaning of each code is broadly similar across providers, the exact format and range of possible responses can vary, so it’s important to consult network-specific documentation when integrating AVS into your processing logic.

AVS response codes list

Why AVS codes matter

Using AVS response codes as part of your verification process can help reduce fraud without introducing unnecessary friction for customers. Transactions with a full match are generally lower risk than those with partial or no match that can be routed for additional checks or declined.

Integrating AVS also helps with chargeback management. If a transaction is disputed and you can demonstrate a full AVS match, you may have stronger grounds for defending the case with the card networks. In short, AVS improves decision-making at the point of transaction and downstream during dispute resolution.

Implementing AVS for businesses

To implement AVS verification, businesses typically work with their payment processor or gateway to enable AVS checks within the card verification and processing flow. AVS responses can be configured to trigger specific rules — such as declining transactions that show no match or flagging partial match responses for manual review.

Merchants should test AVS logic thoroughly and align it with their risk appetite. A strict approach may reduce fraud but increase false declines. A more flexible configuration may allow for higher approval rates while managing risk through other controls, such as CVV checks and velocity rules.

Combining AVS with other tools, including device fingerprinting and Antom Shield's fraud prevention engine, enhances the robustness of your overall payment strategy. While AVS on its own is useful, its value multiplies when paired with contextual fraud signals and adaptive rules.

Conclusion

AVS response codes provide useful signals that can guide payment decisions. They play a role in preventing fraud, improving approval rates, and giving businesses greater control over how transactions are handled.

Antom supports AVS checks across all major card networks, so you can make informed choices with every payment. By paying attention to these codes, merchants can reduce unnecessary declines and strengthen their verification process.