[Billing] Plan upgrade billed to a different logged-in account — invisible duplicate subscription on former employer's card

TL;DR

On 2026-07-04 I upgraded Pro→Max after hitting usage limits. The checkout silently executed against a different logged-in account — a dormant account from my former employer — and Stripe Link auto-charged their corporate card. For two months I was double-billed: my personal card kept paying for Pro as normal, while a second, invisible subscription billed a card I don't own, with every receipt going to a deactivated mailbox. After discovery it took three more weeks to stop, because the account couldn't be logged into, its Billing tab didn't render, and support (Fin) has no authority to act.

The two accounts

| | Personal account | Former-employer account (dormant) |
|---|---|---|
| Daily use | Yes — all my work | No — last conversation 2025-11-08 |
| Plan on 2026-07-04 | Pro (since 06-11, $22/mo, my card) | Free (its old Pro ended July 2025) |
| What happened on 07-04 | nothing on Stripe | Max 5x created — $110.00 to corporate card via Link (B2UZP6JF-0003) |
| 07-11 | Pro renewed normally, $22 my card | — |
| 08-04 | — | renewed as Pro, $22.00 corporate card (B2UZP6JF-0004) |
| Receipts | delivered to my Gmail | all undeliverable — mailbox deactivated (550 5.2.1) |

Why this is an account-selection defect, not a user mix-up

I upgraded because I had exhausted my Pro limit. Three pieces of billing evidence show that the account that hit the limit cannot be the account that got billed:

1. The billed account was dormant. Its last conversation is 2025-11-08 — eight months before the purchase. An account with zero usage does not hit usage limits. The usage that triggered the upgrade was on my personal account.
2. The $110 invoice has no proration credit. The billed account was on Free, so Max was invoiced at the full $100 + tax. The account I was using — and intended to upgrade — was mid-cycle on Pro; upgrading it would have produced a prorated invoice. (It did exactly that when I later upgraded the personal account to Max on 08-13: $100.00 − $18.13 unused-Pro credit.) I went through an upgrade flow as a Pro user, but was billed as a Free account. Those cannot be the same account.

1. There was nothing on that account to renew. Its billing history reads: $20 (2025-06-17), $20 (2025-07-17) — then eleven months of silence — then a full-price Max subscription out of nowhere on 2026-07-04. This was not an old subscription that kept billing, and not an upgrade of anything existing: the checkout created a brand-new subscription from scratch on an account that had no active plan and no usage.

So the limit warning, the upgrade intent, and my active session were all on the personal account — and the subscription materialized on the dormant one. Somewhere between the UI I was using and the checkout, the account context changed. I cannot see where that happened; Anthropic can. claude.ai supports multiple logged-in accounts, and nothing in the upgrade/checkout flow shows which account you are paying for.

Why nobody could notice for a month

• Checkout showed no account identity, and Link auto-filled the saved corporate card — no card-entry step that might have revealed the wrong context.
• Every receipt for the wrong subscription bounced against a dead mailbox (five 550 5.2.1 bounces on record).
• My own Billing page looked perfectly normal — an uninterrupted Pro. Nothing to investigate.
• The charges surfaced only when my former employer's accounting found them on the corporate-card statement, a month later.

The only party who could detect the problem had no context, and the only person with context had no way to see it.

And once discovered, nobody could stop it

• Sign-in requires an email code → mailbox dead → no login possible.
• Support (Fin), over 20+ days: told me to CC the dead address so cancellation could be processed → said a CC is insufficient → said the CC method was correct after all and refunds "will be issued" → then: "I am an AI agent and I am not able to take actions on accounts, process cancellations, remove cards, or issue refunds" — with no ticket number, no human escalation, and finally a suggestion to file a card dispute instead.
• When my former employer temporarily reactivated the mailbox and I logged in, Settings showed no Billing tab at all (appears org-context dependent — the account also has an API org; same family as #45890). Only later did #settings/billing render, exposing the cancel button.

Cancelled 2026-08-26. The $132 refund is still unresolved (card dispute in progress, per support's own suggestion).

Asks

1. Show which account is being charged in the upgrade/checkout flow, and investigate how checkout can bind to a different session than the active UI account.
2. Require explicit confirmation when Link auto-fills a saved card.
3. Fix Billing-tab visibility for accounts with an attached API organization.
4. Provide a human path for billing issues on accounts whose sign-in email no longer exists — Fin states it cannot act on them.

Correlation & evidence

Invoices B2UZP6JF-0003 / B2UZP6JF-0004 (wrong account) vs. the ZA1KEXU1-* series (personal account) uniquely identify both Stripe customers. Full support-email transcripts, card statements, and screenshots of every state above are available on request.

Related: #45890 · #64814 · #68429
Environment: claude.ai web (Chrome / macOS), Stripe billing (not app store)