Billing is where a SaaS product turns into a business, and it is also where small mistakes cost real money. Stripe is one of the most popular choices for subscription billing because it handles cards, invoices, taxes and payment methods in many countries. This guide covers how a solid integration fits together.
1. Model your plans and prices
Start in Stripe with Products (what you sell, for example "Pro plan") and Prices (how you charge: monthly, yearly, per seat or usage-based). Decide early:
- Monthly and annual billing?
- Free trial, and does it need a card?
- Per-seat pricing for teams?
- Usage-based add-ons?
Keep the plan structure simple at launch; it is easy to add plans, harder to migrate customers off confusing ones.
2. Use hosted checkout and the customer portal
Stripe Checkout and the Customer Portal give you secure, mobile-friendly payment pages for subscribing, updating cards, switching plans and cancelling. Using hosted pages means card details never touch your servers, which greatly reduces your security and compliance burden.
3. Treat webhooks as the source of truth
Your app should not assume a payment succeeded because the user returned from checkout. Instead, listen for Stripe webhook events and update your database when they arrive:
checkout.session.completed: the customer subscribedcustomer.subscription.updated: plan, quantity or status changedinvoice.paid: renewal succeeded, so extend accessinvoice.payment_failed: start your dunning flowcustomer.subscription.deleted: access ends
Verify every webhook signature and make your handlers idempotent, because Stripe can deliver the same event more than once.
4. Handle failed payments gracefully
Cards expire and payments fail. Stripe's automatic retries and reminder emails recover many of them. In your app, show a clear banner asking the user to update their card, keep a short grace period, and only then restrict access.
5. Upgrades, downgrades and proration
When customers change plans mid-cycle, Stripe can prorate charges automatically. Decide whether upgrades apply immediately and downgrades at the end of the period; that is the most common and least surprising behaviour.
6. Invoices, receipts and taxes
Stripe generates invoices and receipts. If you sell internationally, consider automatic tax calculation and make sure invoices include the information your business customers need.
7. Test every path
Use test mode and test cards to run through: new subscription, trial ending, renewal, failed payment, card update, upgrade, downgrade, cancellation and refund. These are the "money paths" that should have automated tests (see our QA checklist before launch).
Common mistakes
- Granting access before the webhook confirms payment
- Not verifying webhook signatures
- Storing card data yourself
- No plan for failed payments
- Hard-coding prices in the app instead of reading them from Stripe
Need help?
We implement secure and seamless payment solutions, including Stripe, for SaaS products and marketplaces such as The Storefront and Mastermind. Book a free consultation or read about our payment integration services. Building the whole product? Start with how much a SaaS MVP costs.