PRD Template for Billing

Example: "Our finance team spends 20+ hours per month manually generating invoices and reconciling payments because our current system does not support proration when users change plans mid-cycle. We have 340 active customers on 4 different pricing plans, and 12% of our support tickets are billing-related (incorrect charges, missing invoices, tax questions). We have also received complaints from 8 EU customers about missing VAT numbers on invoices."

Example: "Primary: Automate 100% of invoice generation and payment collection — zero manual intervention for standard billing cycles. Secondary: Reduce billing-related support tickets from 12% to under 2% of total volume. Compliance: Generate tax-compliant invoices for US (sales tax), EU (VAT), and UK (VAT) customers. Self-service: Customers can view invoices, update payment methods, and download receipts without contacting support."

Example: "As a customer, I want to see a clear breakdown of my charges before payment so that I understand exactly what I am paying for. Acceptance criteria: invoice shows line items with quantity, unit price, subtotal; taxes are itemized separately; any credits or prorations are clearly explained; invoice is available as a downloadable PDF."

Example: "FR-1: The system must generate invoices automatically on each billing cycle date. FR-2: Plan upgrades must take effect immediately with prorated charges; downgrades take effect at the end of the current billing period. FR-3: The system must support billing in USD, EUR, and GBP with automatic tax calculation based on customer location. FR-4: Customers must be able to apply account credits to future invoices. FR-5: The system must generate tax-compliant invoices with configurable fields (VAT number, tax ID, business address)."

Example: "NFR-1: All billing calculations must be accurate to the cent — no floating point errors. Monetary values must be stored as integers in the smallest currency unit. NFR-2: The billing system must maintain 99.99% uptime for payment processing. NFR-3: All billing events must be logged in an immutable audit trail. NFR-4: Invoice PDFs must be generated within 5 seconds. NFR-5: The system must retain all billing records for 7 years per financial record-keeping requirements."

Example: "Metric 1: Invoice automation rate (invoices generated without manual intervention). Target: 100%. Metric 2: Billing-related support tickets. Baseline: 12% of total. Target: under 2%. Metric 3: Payment collection rate (first attempt). Baseline: 91%. Target: 96%. Metric 4: Self-service portal adoption (customers who manage billing without support). Target: 80%. Metric 5: Time for finance team to close monthly books. Baseline: 5 days. Target: 1 day."

Example: "We will use Stripe Billing as the billing engine, handling invoice generation, payment collection, and dunning. Our application stores a reference to the Stripe customer, subscription, and invoice IDs. All billing state changes are received via Stripe webhooks and processed idempotently. Tax calculation uses Stripe Tax for automatic sales tax and VAT. Our application provides the customer portal for viewing invoices and managing payment methods, with Stripe's Customer Portal as a fallback."

Example: "Risk: Customers are double-charged due to webhook processing failure and retry. Likelihood: Medium. Impact: Critical. Mitigation: Implement idempotent webhook processing using event IDs. Every charge creation checks for existing charges with the same idempotency key. Risk: Tax calculations are incorrect for a specific jurisdiction, creating tax liability. Likelihood: Medium. Impact: High. Mitigation: Use Stripe Tax for automated tax calculation. Quarterly audit of tax rates against published rates for top 10 customer jurisdictions."