Recurring billing: how we integrated SaaS subscriptions with Stripe

Charging once is simple. Charging every month, from multiple clients, with different plans, mid-cycle plan upgrades and a card that expires at the worst possible time — that's a whole different project inside the project.

In the clinic management SaaS, each subscription has a plan with different limits (number of professionals, appointment volume), and all that recurring billing logic is integrated via Stripe: subscription creation, webhooks for confirmed or failed payments, and automatic access suspension in case of non-payment.

The part that demands the most attention isn't the billing itself, it's what happens in the edge cases: what to do when a payment fails but the client has already been using the system for months, how to handle a downgrade mid-cycle, how to reactivate a suspended account without losing its history.

That kind of edge-case logic is what separates a subscription system that just works from one that generates a support ticket every week.