How to Fix Claude Billing ZIP Code Errors

Understanding Address Verification System (AVS) Failures

When inputting your credit card details for a Claude Pro subscription, you may encounter an error stating that your ZIP or postal code is invalid, or that verification has failed.

This error is triggered by the Address Verification System (AVS), a security measure used by Stripe (Anthropic's payment processor) to detect fraud. AVS compares the billing ZIP or postal code you entered on the checkout screen with the exact billing address on file with your credit card issuer. If they do not match perfectly, the transaction is declined to protect against unauthorized card use.

Steps to Fix ZIP or Postal Code Verification Errors

1. Match Card Details with Bank Statements Exactly Even minor formatting differences can cause an AVS decline. You must enter your address exactly as it appears on your physical paper statements or your official online banking profile.

1. Log into your credit card or bank account portal.
2. Go to your profile or statements tab and locate your official Billing Address.
3. Note the exact formatting of your street number, apartment/suite designation, and ZIP/postal code.
4. When entering this information on the Claude subscription checkout, replicate the formatting precisely. Do not use abbreviations if your bank spells out the words (e.g., write "Suite" instead of "Ste", or "Street" instead of "St" if that is how your statement displays it).

2. Format International Postal Codes Correctly If you are paying with a non-US card, postal code systems can be highly sensitive to spacing and capitalization.

1. For UK postal codes, ensure you include the single space in the middle (e.g., SW1A 1AA instead of SW1A1AA).
2. For Canadian postal codes, use the standard alternating letter-number-letter format with a space in the center (e.g., K1A 0B1).
3. Do not include leading or trailing spaces in the input field.
4. If your country does not use postal codes, try entering 00000 or leaving the field blank if the system permits, though a card registered to a region without a postal code may require you to contact your bank to ask what placeholder value they expect for online transactions.

3. Clear Browser Autofill Profiles Browsers often automatically fill in billing address fields with outdated or incorrect location data stored in your local profile, which overrides your manual inputs without your knowledge.

1. Open the Claude checkout page.
2. Instead of clicking the autofill prompts that appear in the fields, manually type out every single character of your card number, expiration date, CVV, and postal code.
3. Alternatively, use an Incognito or Private browsing window where autofill profiles are disabled by default.
4. Ensure you do not have any active browser extensions that manage password or address forms automatically filling in the hidden billing fields.

4. Contact Your Issuer to Verify AVS Support Some credit card issuers—especially those offering prepaid cards, virtual cards, or cards issued by smaller local credit unions—do not fully support external AVS queries.

1. Call the customer service number on the back of your card.
2. Ask the representative if your card supports "Address Verification System (AVS) requests for international web transactions."
3. Verify whether they have flagged or blocked a recent verification attempt from "Stripe" or "Anthropic."
4. If your card does not support AVS checks, you will need to use a different credit or debit card that does.

When to Escalate

If you have confirmed that your bank statement details match your input exactly and your bank reports that they are approving the transaction but Stripe continues to reject the postal code, contact support.

Reach out via the support portal at support@anthropic.com. Provide the issuing country of your card and confirm that you have verified the billing address details directly with your card provider. Do not send your full credit card number or CVV in any email correspondence.