[BUG] Unable to upgrade to Max 20x

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Every attempt to upgrade from Pro to Max 20x on claude.ai fails with:

Payment failed. Please try again later. If the problem persists, contact support at https://support.anthropic.com/

Steps to Reproduce

1. Log into claude.ai with an active Pro subscription
2. Navigate to Settings → Billing
3. Attempt to upgrade to Max 20x
4. Enter card details
5. Payment fails with the above error

What Should Happen?

The payment should be processed successfully and the account should be upgraded to the Max 20x plan, consistent with how other payment types (e.g., extra usage purchases) are handled on the same account.

Error Messages/Logs

Payment failed. Please try again later. If the problem persists, contact support at https://support.anthropic.com/

Steps to Reproduce

Log into claude.ai with an active Pro subscription
Navigate to Settings → Billing
Click "Upgrade" to Max 20x plan
Enter valid card details
Submit payment
Observe: "Payment failed. Please try again later." error appears

Reproduced across multiple cards, browsers, and devices. The error is consistent and immediate.

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

N/A — This is a claude.ai billing issue, not a Claude Code CLI issue. Reporting here as it is the most actively monitored Anthropic repository.

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_