[BUG] Cannot upgrade Pro → Max: "billing address changed" error blocks annual subscriber

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?

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version

What's Wrong?

Attempting to upgrade from an active annual Pro subscription to Max fails with the following error in Settings → Billing:

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

Support documentation states the workaround is to cancel Pro and wait until the end of the billing period before resubscribing to Max. In my case, the annual Pro subscription doesn't end until March 2027 — nearly a year away. Canceling and waiting is not a reasonable path for an active paying customer trying to upgrade (i.e., pay Anthropic more money).

Expected Behavior

The upgrade flow should either:

1. Allow the billing address to be updated as part of the upgrade transaction, or
2. Provide a clear in-product path to contact a human support agent who can unblock it manually.

Actual Behavior

• Upgrade is hard-blocked in the UI.
• Support chat (Fin AI bot) does not escalate to a human agent.
• No response from support@anthropic.com after 24+ hours.

Steps to Reproduce

1. Hold an active annual Pro subscription with a billing address that has changed since the last invoice.
2. Log into claude.ai → Settings → Billing.
3. Click "Upgrade to Max".
4. Error message appears, blocking the upgrade.

Account Details

• Country: Chile
• Plan: Pro (annual, ends March 2027)
• Desired plan: Max

Impact

Paying customer unable to upgrade. This is direct lost revenue for Anthropic and a poor experience for a long-term subscriber.

Related Issues

• #56281 (Max 5x → Max 20x upgrade fails, support unresponsive)
• #57122 (Pro → Max upgrade fails, payment system issue)
• #55917 (Pro → Max upgrade failure)

Filing here because, per other reports, this is the only Anthropic repository that appears to be actively monitored for billing/platform issues.

What Should Happen?

The upgrade from Pro to Max should complete successfully. Either:

1. The billing address should be editable inline as part of the upgrade flow, or
2. The "contact Support" message should route the user to a human agent who can unblock the upgrade within a reasonable timeframe (24-48h), instead of an AI bot that closes the conversation without escalation.

For annual subscribers specifically, the current workaround (cancel and wait until period end) is not viable when the renewal date is months away.

Error Messages/Logs

Steps to Reproduce

1. Hold an active annual Pro subscription where the billing address on file differs from the address used on the last paid invoice.
2. Log into claude.ai.
3. Navigate to Settings → Billing.
4. Click "Upgrade to Max".
5. Observe error message: "Your billing address has changed since your last invoice. To upgrade to Max, please contact Support for assistance."
6. Upgrade flow is blocked. No in-product path to a human support agent.
7. Contact support@anthropic.com and the in-app support chat — no response after 24+ hours; AI bot does not escalate.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

LAtest

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_