Cancel Subscription

Stop the subscription renewing; the plan runs to the end of the period.

Deliberately not an immediate downgrade. The period is paid for, and taking the plan away the moment someone clicks cancel would be charging for time then withholding it. The drop to free happens when Stripe fires customer.subscription.deleted at the period end, on the same webhook path as any other ending — one implementation, not two.

This is the only path that cancels anything automatically. The § 312k BGB Kündigungsbutton (app/routes/cancellation.py, backend#372) is login-free by law and therefore records a declaration and hands it to support instead — an unauthenticated claim on an email address is not evidence of who is asking. Here require_team_admin establishes identity and authority together, which is what makes acting immediately safe.