Automate Billing and Subscription Management

This skill covers automated billing systems: recurring billing, invoice generation, dunning management (failed payment recovery), proration for plan changes, and tax calculation. Its process: define plans, pricing, billing intervals, and proration rules; map the subscription lifecycle (renewal, cancellation states); implement invoicing, payments, retries, and dunning workflows; model taxes and compliance requirements per region; and validate with sandbox payments before reconciling ledger outputs. A detailed implementation playbook (resources/implementation-playbook.md) covers deeper patterns, checklists, and templates.

Use this when implementing SaaS subscription billing, automating invoice generation and delivery, managing failed payment recovery (dunning), calculating prorated charges for plan changes, handling sales tax/VAT/GST, processing usage-based billing, or managing billing cycles and renewals.

Not the right skill for a one-off invoice or manual billing process, for tasks unrelated to billing or subscriptions, or when pricing/plans/billing flows can't actually be changed.

Inputs: subscription plans and pricing, billing intervals, proration rules, and regional tax/compliance requirements.

Outputs: recurring billing and invoice generation, dunning workflows for failed payments, prorated charges for plan changes, calculated taxes (sales tax/VAT/GST), and reconciled ledger outputs - validated against sandbox payments before production, since production billing must never charge real customers during testing.

Designed to work with whatever payment processor and billing platform is in use; the skill provides the billing logic and lifecycle patterns rather than a specific vendor integration.

Developers building SaaS subscription billing systems who need recurring billing, invoicing, dunning, proration, and tax handling done correctly and validated safely before production.