Subscription Billing Infrastructure Checklist for SaaS Teams

Most SaaS teams start billing with a basic Stripe integration and a few webhook handlers. That setup works at low volume. It breaks at scale — or when you add a second plan tier, or introduce annual billing, or need to support enterprise invoices. Before your billing system becomes a patchwork of fixes, use this checklist to audit what you have and identify what is missing.

Core Payment Processing

• Payment method storage: Card data is tokenized through your payment provider. You never touch raw card numbers.
• Multiple payment methods per customer: Customers can add a backup card and designate a default.
• Account Updater enabled: Your payment processor automatically refreshes expired or reissued card details with Visa and Mastercard networks.
• SCA compliance: Strong Customer Authentication (3DS2) flows are implemented for European customers where required.
• Currency support: If you serve international customers, you have mapped which currencies you accept and how exchange rates are handled.

Subscription Lifecycle Management

• Plan creation and retrieval: Plans are defined in your billing provider and referenced by ID — not hardcoded prices in application code.
• Subscription creation: New subscriptions are created atomically with the customer record. There is no state where a customer exists in your database without a corresponding billing record.
• Trial periods: If you offer trials, the trial end date is stored and the transition to paid is handled automatically by your billing provider.
• Upgrade and downgrade paths: Mid-cycle plan changes calculate proration correctly. Downgrade credits are applied to the next invoice, not discarded.
• Cancellation flows: Customers can cancel via self-service. Cancellations are set to cancel_at_period_end by default, not immediate termination.
• Reactivation: Customers who cancelled during the grace period can reactivate without re-entering payment details.

Webhook Handling

• Signature verification: Every incoming webhook is verified using your provider's signature header. Unverified requests are rejected.
• Idempotent handlers: Webhook handlers are idempotent — processing the same event twice does not create duplicate records or charges.
• Event logging: All received webhook events are logged with their payload and processing status.
• Dead-letter handling: Webhook events that fail processing are queued for retry or flagged for manual review. Silently dropping failed events is not acceptable.
• Critical events handled: At minimum, your system handles invoice.payment_failed, invoice.payment_succeeded, customer.subscription.deleted, and customer.subscription.updated.

Dunning and Revenue Recovery

• Automated payment retry: Failed payments are retried on a smart schedule — not a fixed 24-hour interval. Retry logic accounts for failure code type.
• Pre-expiry notifications: Customers with cards expiring in the next 30 days receive an automated reminder.
• Dunning email sequence: A multi-step notification sequence fires after a payment failure, escalating over 7 to 14 days.
• Self-service payment update: Every dunning notification links directly to an authenticated card update page. No login navigation required.
• Grace period policy: Access is not suspended immediately on payment failure. The grace period length is defined, documented, and communicated to customers.
• Recovery rate tracking: You measure what percentage of failed payments are ultimately recovered, segmented by failure type.

Invoicing and Revenue Recognition

• Invoice generation: Invoices are generated automatically at each billing period. Customers can access past invoices from their account.
• Invoice line items: Each invoice clearly itemizes what is being charged — plan name, period, any prorations, and applicable taxes.
• Tax handling: Sales tax or VAT is calculated and applied correctly by jurisdiction. You are not applying a flat rate to all customers.
• Manual invoicing: You have a path to issue a custom one-off invoice for enterprise deals or professional services without disrupting the subscription cycle.
• Credit notes: When issuing refunds or prorated credits, a credit note is generated against the original invoice for accounting integrity.

Metered and Usage-Based Billing (If Applicable)

• Usage event pipeline: Usage events are captured server-side, timestamped in UTC, and delivered to your billing provider reliably.
• Aggregation and deduplication: High-volume usage is aggregated before reporting to avoid rate limits. Duplicate events are detected and suppressed.
• Customer usage dashboard: Customers can see their current period usage and projected cost before the invoice is finalized.
• Usage alerts: Customers can set thresholds that trigger a notification when usage approaches a defined limit.
• Reconciliation: Actual usage logged in your system is reconciled against what your billing provider invoiced. This runs automatically on a regular schedule.

Reporting and Analytics

• MRR tracking: Monthly recurring revenue is calculated from active subscription data, not from payment volume. Proration charges are excluded from MRR.
• Churn reporting: Voluntary and involuntary churn are tracked separately. Involuntary churn shows you dunning performance.
• Cohort retention: You can see what percentage of subscribers from any given month are still active today.
• Revenue by plan: You can break down revenue contribution by plan tier at any point in time.

Security and Compliance

• PCI DSS scope minimized: Card data handling is delegated entirely to your payment processor. Your servers do not store, process, or transmit raw card data.
• Billing data access controls: Only authorized internal roles can view customer billing records and payment method details.
• Audit log: Changes to subscription state — plan changes, cancellations, manual adjustments — are logged with timestamp and the actor who initiated the change.

If your current billing system has gaps against this checklist, they will surface as customer complaints, revenue leakage, or a painful engineering project under pressure. Start a conversation with Clixo to build or upgrade your subscription billing infrastructure properly.