Invoices and proration

Prepare one billing candidate

A billing run identifies a subscription interval and a frozen set of commercial and usage inputs. It records the plan version, accepted effective changes, aggregate event evidence and tax result. Retries with the same source identity return the earlier candidate. Another run cannot issue a second invoice for the same subscription interval and billing revision.

Preparation may expose missing terms, usage conflicts or an unavailable tax response. Keep those exceptions on the run. A worker completing most of the calculation does not authorise an incomplete document. Review the exact input set and any customer-facing adjustments before approval.

Explain each line on the document

Recurring lines describe the agreed period and base or per-unit commitment. Usage lines retain the meter aggregate and tier calculation. Proration lines preserve the old credit and new charge with their effective time fraction. An adjustment points to its authorised business reason rather than hiding inside a revised rate.

Invoice subtotal sums net line amounts. Tax is calculated from the preserved provider result or reviewed effective rules and added once to that subtotal. Keep line net, tax and gross amounts distinct so a taxable invoice cannot accidentally include tax in its subtotal and add the same tax again at the header.

Review and issue the invoice

The Billing Manager independently approves the candidate revision. The issue action checks that the accepted subscription, usage and tax evidence still match that approval. It then creates the invoice number and freezes the document, lines and source references together. Email delivery remains a separate observed outcome.

A repeated issue command returns the same invoice. A source edit after review invalidates approval before another document can be issued. Once an invoice is issued, changing a product description or price plan cannot alter what the customer received. The system retains its PDF or equivalent document digest alongside the financial amounts.

Correct an issued charge

A credit note references the original invoice and specific line amounts. The independent reviewer checks the remaining creditable net and tax amounts, currency and reason. Concurrent credits cannot consume the same remaining charge twice. Issuing a credit reduces the collectible balance once and preserves the original document.

A credit note is distinct from returning cash. If the customer has already paid, the configured refund action needs its own authorised provider instruction and observed result. A provider timeout stays unresolved; it cannot be interpreted as either a completed refund or permission to submit another unrelated refund request.

Apply a late usage correction

A reviewed adjustment re-rates the corrected original usage and subtracts what was already billed and corrected. A positive remaining difference becomes a uniquely linked later invoice line or standalone correction invoice. A negative difference follows the original-line credit process. Preserve the corrected event set and the original plan so the same late event cannot be billed twice.

Keep billing and accounting boundaries clear

This product owns subscription terms and billing evidence. The payment provider owns its collection outcome, while the accounting connection owns any ledger posting or revenue-recognition implementation. An issued invoice is not proof that cash settled or revenue was recognised. Reconcile the outgoing document identity and external acknowledgment separately. The customer can still inspect their charge and correction history while staff investigate an accounting or delivery exception.