Zip code verification (AVS) and AMEX fails

Payments + Shipping & Fulfilment
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Topic summary

AVS (Address Verification System) postal/ZIP code checks appear to fail specifically for AMEX, while working for Visa and Mastercard. The merchant cites Shopify’s note that if a provider doesn’t support AVS/CVV, the charge may still authorize, but questions whether AMEX should lack support.

Shopify staff explains AVS requires the entered ZIP to match the issuer’s billing address and suggests keeping “Decline charges that fail AVS postal code verification” enabled in Fraud Prevention. They advise customers verify the billing info on file.

The merchant clarifies the problem is the absence of an AVS error when there should be one for AMEX mismatches. Another merchant reports a similar experience and adds PayPal to the list, wondering if this is AMEX-related.

Current status: No confirmed cause or fix identified; uncertainty remains whether this stems from AMEX support, PayPal/third‑party routing, or a platform issue. Suggested next steps: verify Fraud Prevention settings remain enabled, confirm cardholder billing details, and escalate to Shopify Support/payment providers to confirm AVS support and behavior for AMEX/PayPal transactions.

Summarized with AI on January 12. AI used: gpt-5.
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Hey, @egg20292999a .

Rio here from the Shopify Community team. Thank you for reaching out to us about the issue with zip code verification not working for AMEX cards.

The zip code entered must match what is on file with their credit card company. That error would indicate that it does not match.

There is a section in your Fraud Prevention to Disable “Decline charges that fail AVS postal code verification”, however, we highly recommend keeping these features.

The user could check their credit card statement to ensure they are using the billing info on their account.