[BUG] [Billing] Pro Annual → Max upgrade blocked by "billing address has changed" error, no human support available

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?

Pro Annual subscriber attempting to upgrade to Max 5x. The upgrade page shows: "Your billing address has changed since your last invoice. To upgrade to Max, contact Support for assistance." BUT TOTALLY NO ASSISTANCE CAN BE REACHED.

<img width="440" height="290" alt="Image" src="https://github.com/user-attachments/assets/a3d5d5b8-ec10-4be3-a148-18b795d033c2" />

What Should Happen?

Upgrade should process normally. If a billing address mismatch blocks the upgrade, human support should be reachable to resolve it. After 40+ attempts requesting "talk to a person" in the Fin support chat, no human agent was ever connected.

Error Messages/Logs

"Your billing address has changed since your last invoice. To upgrade to Max, contact Support for assistance."

Steps to Reproduce

Log in to claude.ai with an active Pro Annual subscription
Go to Settings > Billing > Adjust plan
Select Max 5x
Error appears: "Your billing address has changed since your last invoice"
Update payment method with correct billing address — error persists
Contact Fin support chat — requested human escalation 40+ times, no human agent connected

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

N/A - this is a claude.ai billing issue, not a Claude Code bug

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Plan: Pro Annual, paid $200 on Feb 20, 2026. Pro-rata credit shows $147.77. Payment method: Visa ending 4682 via Stripe Link. Fin support chat confirmed this requires manual backend intervention but was unable to escalate to a human agent.

<img width="440" height="290" alt="Image" src="https://github.com/user-attachments/assets/a64a20fe-ea77-45c4-b5ca-bad2e7248236" />

<img width="991" height="568" alt="Image" src="https://github.com/user-attachments/assets/1628a1c5-ef02-4af6-b820-40be9e9e980f" />

<img width="537" height="675" alt="Image" src="https://github.com/user-attachments/assets/5765e231-f9bb-4b69-8026-ca109563ad58" />