[BUG] Incorrectly charging VAT to EU B2B customers

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?

Anthropic incorrectly charges VAT on EU B2B invoices despite having a valid VAT number on file.

What Should Happen?

Anthropic should not charge VAT to EU B2B customers when a valid VAT number is on file.

Error Messages/Logs

Steps to Reproduce

1. Open an API account
2. Enter Company Information including valid VAT ID
3. Purchase API credits
4. Receive incorrect invoice including illegal VAT charges

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.220

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

Issue #42018 was closed without any solution. It's critical bug.
Issue #84206 was closed without any solution. It's critical bug.

This is not the #84203 duplicate. It's separate, more important bug.