AVS and card verification codes

Understand AVS and CVD

 

The issuer responses empower merchants with the knowledge to approve, review or decline card-not-present transactions based on match, partial match or mismatched responses.

• Address Verification Service (AVS): Compares customer billings address to issuer records
• Card Verification Data (CVD): 3 or 4 digit code on the card (CVV2, CVC2, CVD and CID)

 

How AVS works

1. At authorization, the gateway/transmitter sends billing address fields (street line and postal code / ZIP) and — if collected — the card security code to the issuer via the card network
2. The issuer returns an AVS response code indicating the level of match (full, partial, none, unsupported, or unavailable). The exact code set or mapping can vary by card brand, acquirer and whether the issuer is domestic vs international

 

Why this matters

 

Understanding AVS and CVD responses is critical for:

• Fraud prevention: Helps detect stolen or fraudulent cards by checking if the billing address and verification code match the issuer’s records. Click here to learn more about fraud prevention
• Cardholder chargeback reduction: Accurate verification reduces disputes and potential losses for you business
• Risk assessment: Full matches indicate lower risk, partial or missing information flags transactions for manual review
• Regulatory compliance: Many card networks and financial institutions require AVS/CVD checks for card-not-present transactions to optimize interchange cost.

Using these tools effectively ensures safer transactions and protects both your business and your customers.

 

Examples of results

 

Card networks use a range of alphabetic codes; different processors map their raw responses to those standard codes. Broadly you can group them like this:

• Full match — issuer indicates both address and postal code match (e.g., Y, X, M depending on network). Lower fraud risk
• Partial match ️— street matches but ZIP does not, or ZIP matches but street does not (e.g., A, P, R). Requires manual review or adaptive rules
• No match — street and/or ZIP do not match (N, C, F). Elevated risk — consider decline or verification
• Not supported / issuer unavailable — AVS not supported by issuer or system unavailable (S, U, R, G). Treat as “unknown” and combine with other signals (CVD, 3DS, device/IP) before decision

Note: Some codes are specific to international issuers or networks (Visa domestic vs international codes). Always check how your acquirer maps raw responses.

AVS Guide:

 

The table below summarizes common codes and their meanings, so you can quickly assess whether a transaction is likely valid or requires review:

 

CVD Guide:

 

In addition to AVS, these codes confirm whether the security number on the card matches the issuer’s records, adding an extra layer of fraud protection. The table below highlights typical CVD codes and what they indicate:

 

AVS and CVD FAQs

 

Find below frequently asked questions and answers on address and card verification: