Fix Claude Postal Code Verification Failed

When upgrading to Claude Pro or adding credits to your developer console account, you may encounter a billing error that reads "Your card's security code or postal code verification failed." This occurs when the payment gateway, Stripe, runs an Address Verification System (AVS) check and finds a mismatch between the ZIP/postal code you entered and the address register of your card issuer.

Follow these troubleshooting steps to resolve the error and successfully complete your purchase.

Understand Why AVS Fails

Before trying again, note that even if you enter your correct postal code, the verification can fail for several hidden reasons:

• Incorrect format: Extra spaces, missing hyphens, or wrong character cases.
• Outdated banking data: You recently moved, and your card issuer hasn't updated your primary billing address.
• Prepaid or virtual cards: Many virtual or prepaid gift cards lack a registered billing address, making online verification fail automatically.
• International processing blocks: Your bank blocks charges from foreign entities (Anthropic is based in the US).

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Step 1: Match Your Billing Address to Your Bank Statement

Do not guess your billing address. The information must match your card issuer's exact records.

1. Log in to your banking application or open your last digital credit card statement.
2. Locate the exact formatting of your billing address, paying close attention to the postal code or ZIP code.
3. Go back to the Claude checkout screen.
4. Enter the postal code exactly as it appears on your statement. For US ZIP+4 codes, try entering just the first 5 digits, and then try entering the full 9 digits with a hyphen if the first attempt fails.

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Step 2: Clear Session Data and Cache

Stripe occasionally caches failed payment attempts in your browser's local storage. This can cause the checkout page to repeatedly submit outdated address data.

1. Open an Incognito / Private Window in your browser.
2. Navigate directly to claude.ai and log in.
3. Go to the upgrade screen and attempt to re-enter your payment details from scratch.
4. Alternatively, clear your browser's cookies and site data for anthropic.com and stripe.com.

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Step 3: Register Your Virtual or Prepaid Card

If you are using a virtual card (like Privacy, Revolut, or Wise) or a prepaid credit card, Stripe will reject it if no billing address is tied to the token.

1. Open the app of your virtual card provider.
2. Go to the specific card's settings and look for Billing Address or Edit Billing Zip.
3. Assign your actual home address to the virtual card.
4. Wait 5 minutes for the system to update, then attempt the Claude checkout process again.

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Step 4: Contact Your Bank to Clear Holds

Every time you receive a postal code verification error, Stripe may place a temporary validation charge (usually $0.00 or $1.00) on your card. If you attempt the purchase too many times, your bank's fraud detection system may block further requests.

1. Call the customer service number on the back of your card.
2. Tell the agent: "I am attempting to make a purchase at Anthropic/Stripe. The address verification is failing. Can you tell me what address format you have on file, and ensure payments to Stripe are not being blocked?"
3. Ask them to manually authorize any pending holds from Anthropic.

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When to Escalate

If you have confirmed with your bank that the billing address matches perfectly, your card has sufficient funds, and the bank is not blocking the transaction, the problem may be an issue with Stripe's routing for your regional currency. Open a support ticket via the helper widget on [Anthropic's support site](https://support.anthropic.com/) and provide a screenshot of the exact error code (without showing your full card number).