Subscription Proration Agent
Calculates and applies mid-cycle proration credits and charges automatically whenever a customer upgrades, downgrades, or changes seat count on a subscription.
Finance teams today manually recalculate prorated amounts in spreadsheets whenever a customer changes plans mid-cycle, a process that is slow, inconsistent across reps, and prone to rounding and date errors that erode customer trust
Different plan tiers, billing anniversaries, and partial-month scenarios each require distinct math, and support agents often apply the wrong formula or forget to prorate at all, leading to billing disputes and revenue leakage
This agent ingests the subscription change event in real time, determines the exact proration window down to the second, and applies the correct credit or charge to the customer's next invoice or immediately if configured
It also documents the calculation logic on the invoice line item so customers and auditors can see exactly how the amount was derived
The agent subscribes to plan-change events from the subscription management system, pulls the current plan terms, billing anniversary date, and usage-to-date, then runs a deterministic proration engine that supports daily, hourly, and second-level granularity. It writes the resulting credit or debit line items directly to the invoicing system via API, tags them with the originating change event ID for traceability, and triggers a customer-facing notification summarizing the adjustment. Configurable rules let finance define whether proration is credited immediately or rolled into the next invoice.
Detect Plan Change Event
- Listen for upgrade, downgrade, and seat-change webhooks
- Capture effective date and time of the change
- Pull prior and new plan pricing details
- Validate the customer's current billing status
Calculate Prorated Amount
- Determine remaining days in the current billing cycle
- Apply the configured proration method (daily, hourly, none)
- Compute both the credit for unused time and the charge for new terms
- Round according to finance-defined currency rules
Apply Adjustment to Invoice
- Post credit and debit line items to the billing ledger
- Attach calculation notes to each line item
- Route high-value adjustments above threshold for manager review
- Sync updated invoice totals to the accounting system
Notify and Reconcile
- Send the customer a plain-language summary of the adjustment
- Log the event in the audit trail
- Flag anomalies such as negative invoice totals for review
- Update revenue recognition schedules to reflect the change