Charging correctly, every month.
WHAT THE SYSTEM MUST HANDLE
Plans and their prices Trials Upgrades and downgrades Proration Cancellations Failed payments Refunds Tax Invoices
WHY PRORATION IS THE HARD PART
Mid-cycle changes require calculating partial periods correctly, and errors are visible on the invoice.
WHAT TO DECIDE
What happens when a customer upgrades mid-cycle What happens when they downgrade Whether cancellation ends immediately or at period end
WHAT TO PREFER
Cancellation at period end, since they paid for it.
WHAT TO NEVER DO
Charge without a clear invoice Change amounts silently Make cancellation difficult
WHY THAT LAST POINT
It produces disputes, chargebacks and public complaint, and in some jurisdictions it is unlawful.
WHAT TO BUILD OR BUY
Billing is a solved problem, and building it consumes months.
WHAT TO USE
An established provider or billing platform.
WHAT TO KEEP IN YOUR OWN SYSTEM
The record of what each customer is entitled to.
WHY
Entitlement drives the product, and it must work when the billing provider is unreachable.
WHAT TO RECONCILE
Your records against the provider's, regularly.
WHAT TO ALERT ON
Discrepancies, which indicate a defect affecting money.
