[BUG] Magic-link and Google login both route existing Max subscriber to "Let's create your account" onboarding; mobile session and Console remain authenticated

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?

What's Wrong?

Signing in to claude.ai in any browser, and in the Claude Desktop app,
completes authentication and then drops me on the onboarding screen
reading "Let's create your account — a few things for you to review",
instead of my existing account.

Account: Max plan, individual. Email: tomasvgorp @ gmail.com
Location: Portugal.

I have deliberately NOT clicked "Create account", to avoid the duplicate
account outcome documented in #51002.

Steps to reproduce

1.⁠ ⁠Open claude.ai in any browser, or the Claude Desktop app on macOS.
2.⁠ ⁠Sign in with "Continue with email" using the account address.
Authentication succeeds.
3.⁠ ⁠Land on "Let's create your account" instead of the existing account.
4.⁠ ⁠Same result with "Continue with Google".
5.⁠ ⁠Same result in a private window, and on a second device that has
never touched the account, on a different network.

What Should Happen

The verified identity should map to my existing Max account record.

Sessions still authenticated

•⁠ ⁠Claude mobile app (chats, projects, skills, Max plan all intact,
Settings shows the same address)
•⁠ ⁠Claude Console at platform.claude.com

Troubleshooting already done

•⁠ ⁠Repeated attempts with the exact account address
•⁠ ⁠Both login methods
•⁠ ⁠Private browsing
•⁠ ⁠Revoked the "Sign in with Google" connection per help article
13189465, then retried both methods. No change.
•⁠ ⁠Second device, second network. Same onboarding screen. This rules
out local cache, cookies and service worker state.

Support path

Reported through the in-app "Get help" messenger and through the
"I can't login" flow on support.claude.com. Both lead to the Fin AI
agent. Fin confirmed no organization is attached to my address,
then stated it cannot open a tracked case, cannot route to a separate
Product Support team, and that no human reply is coming. Anthropic's
"How to get support" article (9015913) states Pro and Max subscribers
receive further assistance from the Product Support team and that Fin
passes inquiries along when investigation is needed. That did not happen.

Prior reports of the same failure mode

#36797 (Mar 2026), #39788 (Mar 2026), #51002 (Apr 2026),
#57164 (May 2026), #58566 (May 2026), #60022 (May 2026),
#74236 (Jul 2026).

Note on scope: this is the shared account authentication service, which
Claude Code login also depends on (see #77966), which is why these
reports land in this repository. Earlier instances were closed as
invalid or went stale without a posted fix.

Environment

•⁠ ⁠macOS, Claude Desktop app and Chrome/Safari
•⁠ ⁠Also reproduced on a second device on a different network
•⁠ ⁠Plan: Max

What Should Happen?

Completing authentication with the email address on an existing Max
account should map the verified identity to that existing account
record and open it, on every surface, exactly as it already does on
the Claude mobile app.

Instead the backend fails to find or match the record and silently
drops the session into the new user onboarding flow, presenting
"Let's create your account" with the email shown as verified. No
error is surfaced, and nothing tells the user that their existing
account was not matched.

Two secondary expectations:

1.⁠ ⁠When authentication succeeds but no account record is matched for
a verified address that does have one, the flow should surface an
error rather than offering account creation. As documented in
#51002, accepting that offer creates a duplicate under the same
email with a different auth provider and permanently locks the
user out of the original paid account.

2.⁠ ⁠A paying Max subscriber locked out of every surface but one should
have a route to a human. Per help article 9015913, Pro and Max
subscribers receive assistance from the Product Support team and
Fin passes inquiries along when investigation is needed. In this
case Fin stated explicitly that it cannot open a case, cannot
route to a separate team, and that no human reply is coming.

Error Messages/Logs

Steps to Reproduce

Preconditions: an existing Claude account on the Max plan, with an
active authenticated session on the Claude mobile app confirming the
account and its data are intact under the same email address.

 1.⁠ ⁠Open claude.ai in a browser on macOS, or open the Claude Desktop
app.
 2.⁠ ⁠Choose "Continue with email" and enter the account address.
 3.⁠ ⁠Open the login link from the email on the same device.
Authentication completes successfully.
 4.⁠ ⁠Observe: the browser lands on the onboarding screen reading
"Let's create your account — a few things for you to review",
with the email shown as verified, instead of the existing account.
 5.⁠ ⁠Repeat with "Continue with Google". Same result.
 6.⁠ ⁠Repeat in a private browsing window, to exclude cached cookies,
local storage and service worker state. Same result.
 7.⁠ ⁠Revoke "Sign in with Google" for Claude at
myaccount.google.com/connections, per help article 13189465, then
repeat both methods. Same result.
 8.⁠ ⁠Repeat on a second physical device that has never been signed in
to this account, on a different network. Same result. This rules
out any local client state or network as the cause.
 9.⁠ ⁠Open the Claude mobile app: still signed in, all chats, projects
and skills present, Settings shows the same email address.
10.⁠ ⁠Open platform.claude.com: signed in successfully with the same
address, Console organization resolves normally.

Not attempted, deliberately: clicking "Create account" on the
onboarding screen, to avoid the duplicate account outcome in #51002.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.259

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_