[BUG] Billing: EU VAT (BG204655368) not saving / incorrect 20% charge

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?

There is a critical bug in the Anthropic/Claude billing interface that prevents EU VAT numbers from being saved.
Issue: When entering a valid Bulgarian VAT ID (BG204655368), the field fails to persist after clicking "Update".
Result: The account is incorrectly treated as B2C, charging 20% VAT (Total €18.00) instead of the correct €15.00 net (Reverse Charge for B2B as per EU Directive 2006/112/EC).
Support Impact: Manual support (Ticket #215473362291970) has been unresponsive for over 30 days.

What Should Happen?

The Tax ID field should successfully validate and save the VAT number via VIES.
The billing system should recognize the account as a VAT-registered business.
Invoices should be issued at the net price of €15.00 with 0% VAT (Reverse Charge).

Error Messages/Logs

No explicit error message is shown in the UI.
Console Log (if checked): The "Update" request completes, but the tax_id field remains null or empty in the account state.
VIES Status: VAT ID BG204655368 is confirmed as VALID on the official EU VIES validator.

Steps to Reproduce

Log in to Claude.ai and go to Settings > Billing.
Click on Update Tax ID.
Select Bulgaria and enter BG204655368.
Click Update.
Refresh the page or navigate away and back — the field is empty again.
Observe that the next invoice generated is for €18.00 (Full price + VAT) instead of €15.00 (Net).

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

N/A (Billing Portal Bug)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Dear Anthropic Billing Team,

I am writing to escalate an unresolved billing issue that has been ongoing for over a month, reference Conversation ID: 215473362291970.

SUMMARY OF ISSUES:

1. VAT incorrectly included in invoices

I am a VAT-registered business in Bulgaria. My VAT number BG204655368 is valid and verifiable on EU VIES:
https://ec.europa.eu/taxation_customs/vies/#/vat-validation

As a B2B customer with a valid EU VAT number purchasing services from a non-EU supplier, VAT must NOT be charged. The correct treatment is reverse charge (Article 196, EU VAT Directive 2006/112/EC). My invoices should be issued at €15.00 net with 0% VAT.

Instead, I am being charged €18.00, which corresponds exactly to €15.00 + 20% Bulgarian VAT. This has happened on at least two consecutive invoices.

1. Tax ID field does not save — confirmed platform bug

I have repeatedly attempted to enter my VAT number in the billing settings under both "European VAT number" and "Bulgaria Unified Identification Number" options. After clicking Update, the field does not save any value and remains empty. This is a confirmed bug on your platform — it is not a configuration error on my end.

This bug prevents me from resolving the issue myself, making manual intervention from your team mandatory.

WHAT I NEED:

1. Fix the Tax ID field bug so it correctly saves BG204655368
2. Configure my account to invoice at €15.00 net with 0% VAT going forward
3. Issue corrected invoices (credit note + new invoice at €15.00) for all months incorrectly charged

I am not requesting a refund at this stage — I am requesting that this be fixed permanently. I have attached my VAT registration certificate as additional proof.

If this is not resolved within 5 business days, I will proceed with a chargeback through my bank for all incorrectly charged amounts and file a complaint with the relevant Bulgarian consumer protection authority.