[BUG] Buy credits button permanently disabled - tax shows '$--' and never calculates

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?

The "Buy credits" button on the billing modal is permanently disabled even after filling in all required fields. The tax calculation shows '$--' and never resolves, which keeps the button grayed out.

What Should Happen?

Tax should calculate and button should activate after all fields are filled.

Error Messages/Logs

There is no error message but Buy Button isn't activated.

Steps to Reproduce

1. Go to console.anthropic.com → click "Add credits"
2. Select USD 20
3. Fill in all fields: card number, expiry, CVC, email, phone, name, billing address
4. Tax remains '$--' and total remains '$--'
5. "Buy credits" button stays grayed out and unclickable

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.204

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Environment:

• Browser: Chrome (latest)
• Country: South Korea
• Card type: Mastercard (international payments enabled - works on other platforms)
• Tried: incognito mode, multiple attempts