Subscription Billing for SaaS: Plans, Proration, Invoices and Dunning
How subscription billing works for SaaS and service businesses: plans, trials, upgrades with proration, GST invoices, failed-payment recovery and revenue repo
Recurring revenue is the engine of SaaS and subscription businesses, and billing is where that engine meets real money. Get billing wrong and you leak revenue through failed payments, confuse customers with incorrect invoices and spend hours reconciling.
Key takeaways
- Model plans flexibly: tiers, seats, usage and add-ons.
- Proration keeps upgrades and downgrades fair and automatic.
- Dunning recovers a meaningful share of failed payments.
- Revenue metrics like MRR and churn should come straight from billing data.
Core capabilities
- Plans and pricing: monthly, annual, tiered, per seat and usage-based
- Free trials, coupons and discounts
- Upgrades and downgrades with automatic proration
- Recurring payments with cards, UPI AutoPay or bank mandates
- GST-compliant invoices and credit notes
- Customer self-service portal for invoices and payment methods
Recovering failed payments
| Step | Action |
|---|---|
| Day 0 | Automatic retry and notification to the customer |
| Days 1–7 | Smart retries and reminders with an update-payment link |
| Grace period | Limited access with a clear banner in the product |
| End of grace | Pause subscription, keep data, easy reactivation |
Need billing that fits your product? See our invoicing & subscription billing solution or discuss your pricing model.
Metrics that come from billing
MRR and ARR, net revenue retention, churn and expansion revenue all come from billing data. When billing is accurate, these metrics are reliable enough to run the business and report to investors.
Build or buy?
Billing platforms are a great start. Custom billing becomes valuable when pricing is complex, usage must be metered from your product, or invoices and revenue must flow into your ERP with specific accounting rules.
