--- title: How to Audit Invoices Against the Contract | Aavenir url: https://aavenir.com/how-to-maximize-the-value-of-your-invoice-audit-against-contract/ description: An invoice audit against the contract checks rates, scope and terms before or after payment. The common findings, the steps, and how to run it on every invoice. updated: 2026-11-07 --- [Home](https://aavenir.com/) / [Blog](https://aavenir.com/blogs/) / Invoice audit against contract Accounts payable # How to maximize the value of your invoice audit against contract A purchase order match tells you the invoice was expected. A contract audit tells you it was billed the way you agreed. PS **Pranjali Singh**Feb 21, 2023 ยท 4 min read An invoice audit against the contract checks that what a supplier billed matches what the contract allows: the agreed rates, the services in scope, the payment terms, any discounts, caps and service credits. It goes further than matching an invoice to a purchase order, because purchase orders rarely carry every commercial term. Done occasionally, after payment, a contract audit recovers some money and finds patterns. Done on every invoice before payment, it stops overbilling at the source. This guide covers what an audit against the contract involves, what it usually finds, and how to run it routinely. Key takeaways - A contract audit checks rates, scope, terms and credits, not only quantities - Common findings are overbilling, duplicates, late invoicing and missed credits - Start from the contract: extract the commercial terms into checkable data - Run the check before payment, so you prevent rather than recover - Feed findings back into supplier reviews and renegotiation ## What is an invoice audit against the contract? It is a review of supplier invoices against the terms of the governing contract. The auditor, or the software, reads the contract's commercial terms and compares each invoice line against them. Did the supplier charge the agreed rate? Is the service within scope? Was the volume discount applied? Is a price increase allowed yet, and within the cap? Are service credits owed for missed service levels? The audit also looks at the other direction: whether your own side met its obligations, such as paying within the agreed terms. Both matter for a healthy relationship. ## How does it differ from purchase order matching? | Check | Purchase order match | Audit against contract | | Was the purchase expected? | Yes | Yes | | --- | --- | --- | | Quantities received | Yes, with three way match | Yes | | Unit price | Against the purchase order price | Against the contract rate card | | Scope of services | Rarely | Yes | | Discounts, rebates and caps | Rarely | Yes | | Price increase rules | No | Yes | | Service credits owed | No | Yes | A [two or three way match](https://aavenir.com/what-is-2-way-3-way-matching/) is necessary, but a purchase order can carry the wrong price, and many service invoices have no purchase order line detail at all. The contract is the source of truth. ## What does a contract audit usually find? - **Overbilling:**rates above the contract, charges for services outside the agreed scope, or fees the contract does not allow. - **Duplicate invoicing:**the same service billed twice, by error or deliberately. See [how to deal with duplicate invoices](https://aavenir.com/how-to-deal-with-duplicate-invoices/). - **Price increases applied early or above the cap:**escalation clauses usually limit when and how much prices can rise. See [supplier price increase review](https://aavenir.com/use-cases/supplier-price-increase-review/). - **Missed discounts and rebates:**volume tiers or early payment discounts that were agreed but not applied. - **Unclaimed service credits:**service levels missed with no credit on the next invoice. See [service credit recovery](https://aavenir.com/use-cases/service-credit-recovery/). - **Late invoicing:**invoices submitted outside the agreed window, which some contracts allow you to reject. - **Billing outside the term:**charges after the contract ended or before it started. ## What are the steps of a contract audit? - **Review the contract:**identify scope, rate cards, payment terms, discounts, caps, escalation rules, service levels and credits, and the invoicing requirements. - **Turn terms into checks:**record each commercial term as data that an invoice line can be compared against. - **Gather the records:**invoices, purchase orders, receipts, timesheets and service level reports for the period. - **Compare line by line:**check each charge against the matching term and record any variance. - **Document the findings:**list each issue with the clause and invoice reference, and the amount involved. - **Act on them:**request credits or refunds, correct internal process gaps, and raise patterns in the next supplier review or renegotiation. ## How do you run the audit on every invoice? Manual audits are slow, so they tend to happen once a year on a sample, after the money has gone. The better approach is to run the contract check at the point of approval. That requires the commercial terms to be available as data, which is where AI extraction helps. In Aavenir, Aavenir AI reads the executed contract and extracts its rate cards, caps, payment terms and service levels. [Invoiceflow](https://aavenir.com/solutions/accounts-payable-automation/) then checks each incoming invoice against those terms as well as the purchase order and receipt, and routes any variance to an accounts payable specialist with the clause beside the invoice line. A person approves or rejects every exception. See [invoice to contract compliance](https://aavenir.com/use-cases/invoice-to-contract-compliance/). **Audit sample invoices against a real contract**Bring one supplier agreement and a few invoices. We will show Aavenir AI extracting the terms and Invoiceflow checking every line. Schedule a demo ## How do you get the most value from the findings? Findings are worth more than the money they recover. A supplier that repeatedly bills above the rate card needs a conversation, and the evidence makes it a short one. Patterns across suppliers show where contracts are vague and should be tightened at renewal. And clean audit records make external audits faster, because each payment can be traced to the term that justified it. Share results with procurement and the contract owner, not only with finance. ## The bottom line An invoice audit against the contract checks what a purchase order match cannot: rates, scope, caps, discounts and credits. Turn contract terms into data, check every invoice before payment, and use what you find to improve supplier performance and future contracts. ### In this article - What is an invoice audit against the contract? - How does it differ from purchase order matching? - What does a contract audit usually find? - What are the steps of a contract audit? - How do you run the audit on every invoice? - How do you get the most value from the findings? **Stop overbilling before payment**Aavenir AI extracts contract terms, Invoiceflow checks each invoice line, and a person decides every variance. Share [in](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Faavenir.com%2Fhow-to-maximize-the-value-of-your-invoice-audit-against-contract%2F)[X](https://twitter.com/intent/tweet?url=https%3A%2F%2Faavenir.com%2Fhow-to-maximize-the-value-of-your-invoice-audit-against-contract%2F&text=How%20to%20maximize%20the%20value%20of%20your%20invoice%20audit%20against%20contract) Frequently asked questions (FAQ) ## Frequently asked questions ### ### What is an invoice audit against a contract? It is a check of supplier invoices against the governing contract: agreed rates, services in scope, payment terms, discounts, price increase caps and service credits. It catches overbilling that purchase order matching misses. See [invoice to contract compliance](https://aavenir.com/use-cases/invoice-to-contract-compliance/). ### ### What are common findings in a contract invoice audit? Typical findings include rates above the contract, charges outside scope, duplicate invoices, price increases applied early or above the cap, missed volume discounts, unclaimed service credits and billing outside the contract term. Learn more about [spend leakage](https://aavenir.com/glossary/spend-leakage/). ### ### Should invoices be audited before or after payment? Before payment wherever possible. Post payment audits recover some money but depend on supplier cooperation. Checking each invoice against contract terms at approval prevents the overpayment in the first place, and a person still decides every exception. See [Invoiceflow](https://aavenir.com/solutions/accounts-payable-automation/). Have a question we have not answered? [Ask the Expert](https://aavenir.com/contact/) ## Keep reading [Accounts payable How to deal with duplicate invoices Why duplicate invoices get paid, the warning signs accounts payable should watch for, and the controls that stop a second payment before it leaves the bank. Read more](https://aavenir.com/how-to-deal-with-duplicate-invoices/)[Accounts payable How to guard organizations against accounts payable risks The main accounts payable risks: missed due dates, supplier and internal fraud, and poor payment visibility, with the controls that reduce each one. Read more](https://aavenir.com/how-to-guard-organisations-against-accounts-payable-risks/)[Accounts payable Managing IT vendor invoices on ServiceNow IT vendor invoices are complex: many formats, purchase order and non purchase order bills, and constant status questions. How to process them on ServiceNow. Read more](https://aavenir.com/managing-it-vendor-invoices-on-servicenow/) Schedule a demo ## See your contracts run on one record. - **1****A 30 minute walkthrough**Built around your team, whether that is procurement, legal, IT or finance. - **2****Your contracts, not ours**Bring a few sample agreements and watch Aavenir AI extract and review them. - **3****ServiceNow or standalone**We show the deployment that fits the systems you already run. Prefer to talk first? [Contact the team](https://aavenir.com/contact/). The form did not load. [Contact the team](https://aavenir.com/contact/) instead, or refresh the page.