Written cancellation confirmation sent immediately

FTC Click-to-Cancel Rule (2024) requires that a cancellation confirmation be provided to the consumer immediately after cancellation — not only as a UI toast that disappears, but as a durable written record. California ARL and EU Consumer Rights Directive 2011/83/EU Article 12 both require confirmation of contract termination including the date through which access continues. Stripe's Billing Portal handles the portal UI but sends no custom cancellation email by default; the application must handle customer.subscription.updated (cancel_at_period_end) and customer.subscription.deleted webhooks to satisfy this requirement.

Handle the customer.subscription.updated webhook to detect cancel_at_period_end: true and send a confirmation email immediately. In app/api/webhooks/stripe/route.ts:

if (event.type === 'customer.subscription.updated') {
  const subscription = event.data.object
  if (subscription.cancel_at_period_end) {
    const customer = await stripe.customers.retrieve(subscription.customer as string)
    const email = 'email' in customer ? customer.email : null
    if (email) {
      await sendEmail({
        to: email,
        subject: 'Your subscription has been cancelled',
        template: 'cancellation-confirmation',
        data: {
          accessUntil: formatDate(subscription.current_period_end),
          cancelUrl: `${process.env.NEXT_PUBLIC_APP_URL}/settings/billing`,
        },
      })
    }
  }
}

Email text must include: 'Your subscription has been cancelled. You will retain access until [date]. No further charges will be made.'