we are having the same issue, after checking the post code supplied is correct, but payment is still not going through
Topic summary
A merchant is experiencing payment failures due to “invalid zip code” errors for valid UK postcodes. The issue stems from Shopify Payments’ Address Verification System (AVS), which compares the customer’s entered postcode against their card issuer’s records.
Primary cause identified:
- AVS mismatch between checkout entry and bank records
- Formatting sensitivity (spacing/capitalization differences like “SW1A 1AA” vs “SW1A1AA”)
- Card issuer verification requirements
Recommended solutions:
- Customers should verify their postcode matches bank records exactly
- Check that all UK regions (England, Scotland, etc.) are enabled in shipping settings
- Review Shopify Payments AVS configuration settings
Status: Multiple merchants report the same issue. One contributor suggests alternative payment methods (bank-to-bank transfers) that bypass postcode validation entirely. The discussion remains open with troubleshooting ongoing for affected stores.