What subscription billing really has to handle
Charging a card once a month is the easy part. The work is everything around it: a customer starts a free trial, upgrades in the middle of a cycle, adds five seats, applies a coupon, then their card expires. Every one of those moments has to produce the right charge and the right access.
When billing and access drift apart, you either give away paid features for free or lock out paying customers. Both quietly cost you money and trust.
- Monthly and annual plan tiers, plus per-seat and usage-based options
- Free trials with or without a card on file, and clean trial-to-paid conversion
- Proration when customers upgrade, downgrade, or change seat counts mid-cycle
- Coupons, discounts, and promotional pricing that don't corrupt future invoices
- Sales tax and VAT handled based on the customer's location
- Invoices, receipts, and a self-serve billing portal so customers manage their own cards
Where SaaS billing quietly leaks revenue
Most billing bugs aren't dramatic outages. They're silent: a downgrade that never prorated, a webhook processed twice, a failed payment that never triggered a retry so the customer just churned without anyone noticing.
We design for those edge cases up front because they're the ones that show up as unexplained revenue gaps months later.
- Idempotent webhook handling so a retried event never double-charges or double-provisions
- Dunning flows that retry failed cards, email the customer, and set a grace period
- One source of truth for subscription state instead of scattered flags
- An entitlements layer that decides what each subscription unlocks
- An audit trail of billing events for support and reconciliation
- Guardrails on proration and refund math so credits are always correct
More on saas products
Frequently asked questions
Should we build our own billing system from scratch?
Almost never. A dedicated billing provider (like Stripe Billing) already solves card charging, retries, tax, and compliance. The real engineering is the integration: keeping your access control in sync with subscription state and handling the edge cases cleanly. That's where we focus, rather than rebuilding a payments processor.
Can customers change plans in the middle of a billing cycle?
Yes. We can prorate the difference immediately, apply the change at the next renewal, or offer both, depending on what fits your product. The important part is that the charge and the access change together so nobody pays for something they can't use or uses something they didn't pay for.
What happens when a customer's payment fails?
We set up dunning: the system automatically retries the card on a schedule, emails the customer to update it, and holds access during a grace period you define before restricting the account. This recovers revenue that would otherwise churn silently.