How to run a revenue leakage audit

01

Choose a transaction trail

Start with one product line, location or customer group and a closed period. Gather the contract or quote, order, delivery or service record, invoice, credit notes and payment record. Use a shared transaction identifier where possible; where it is missing, document how records were matched.

A missed inquiry or unanswered quote is a possible lost sale, not earned revenue. Track it separately from completed work that may be billable and from an unpaid invoice. Do not add the estimated value of a possible sale to an earned revenue discrepancy.

Give finance and the people responsible for delivery a chance to explain exceptions. An apparent difference may be an agreed discount, tax treatment, timing difference, disputed work or a legitimate credit.

• List unmatched orders, unbilled completed work and invoices without corresponding delivery records.
• Compare agreed prices and quantities with what was invoiced.
• Age unpaid invoices and record the reason for any dispute.

02

Reconcile before estimating a loss

For each completed transaction, compare the amount billable under the agreement with the net amount invoiced after valid adjustments. Then compare the net invoice with payments and outstanding balances. Keep unbilled work and unpaid invoices separate so the same amount is not counted twice.

Illustrative example: a completed order has an agreed billable value of $10,000. The invoice is $9,500 and there is no valid adjustment, leaving a $500 billing discrepancy to investigate. If the customer has paid $8,000, the remaining $1,500 is an outstanding balance on the invoice, not another billing discrepancy. Recovery depends on the agreement and supporting evidence, as well as customer circumstances.

Summarize discrepancies by cause and value, but do not treat every exception as collectible revenue. Check timing, duplicates and credits before reporting a total.

03

Prioritize and fix the handoff

Create one record per exception with its transaction ID, category, amount or estimated opportunity, evidence, reason, age, owner, next action and review date. Link related records so the same amount cannot appear as both unbilled and unpaid. Mark uncertain amounts as estimates and confirmed collections only after payment is received.

First resolve time-sensitive or disputed items with the appropriate finance or legal adviser. Then compare the supported value, likelihood of resolution and effort for the remaining items. Agree who can correct an invoice or contact a customer, and follow your accounting and customer communication procedures.

For a recurring cause, add a control where the record goes missing: for example, reconcile completed work against invoices each week. Track new exceptions, their age and confirmed recoveries separately, and check whether the same issue returns.

• Keep the original record and an audit trail for each correction.
• Review unresolved items at the agreed date and escalate those without an owner or decision.

04

Build an exception register

Use one row per underlying transaction and keep links to its order, delivery record, invoice, adjustments and payment. Add separate columns for the amount potentially unbilled and the amount currently unpaid; neither is confirmed recovery. Include currency and the date each record was taken so timing differences can be investigated.

For example, if one delivery record shows extra work but the contract is unclear, mark the amount as an estimate and assign someone to check the agreement. If an invoice appears unpaid but a remittance exists, ask the accounts team to trace the payment before contacting the customer. Close the exception only after the relevant records agree or the responsible person documents a valid reason for the difference.

• Record the transaction ID, customer and agreement. Include delivery evidence and invoice and payment references.
• Decision: exception type, supported amount, owner, next action and review date.
• Outcome: corrected, disputed, not recoverable or collected; retain evidence for each decision.