Accounts payable is where the money leaves your business (payments to suppliers, contractors, and service providers), which makes it one of the most important areas to audit regularly.
A well-run accounts payable audit prevents overpayments, reduces fraud risk, and surfaces savings. This guide covers what an AP audit is, why it matters, the 8-step process, the internal-control checklist to work through, common mistakes, and how automation changes the picture.
What is an accounts payable audit?
An accounts payable (AP) audit is a detailed review of the financial information recorded in a business’s AP records, essentially all outgoing payments. Done thoroughly, it checks not just the numbers but the efficiency, reliability, and integrity of the payment process.
A complete AP audit confirms that:
- Payments match their invoices and purchase orders
- Vendors are legitimate and properly authorized
- Liabilities are accurately recorded
- Fraudulent or duplicate transactions are detected
Why auditing accounts payable matters
Businesses lose an estimated 5% of revenue annually to fraud, according to the Association of Certified Fraud Examiners, and accounts payable is among the most vulnerable areas because it touches nearly every part of the organization. Weak AP controls lead to losses, compliance issues, and reputational damage.
Regular audits strengthen controls and deliver measurable benefits: detecting unrecorded liabilities, catching duplicate and fraudulent payments, ensuring regulatory compliance, and improving vendor relationships and cash-flow accuracy.
The 8-step accounts payable audit process
A structured audit follows the same sequence each time. Work through these eight steps:
- Plan the audit: define scope, period, and which accounts and vendors to review.
- Gather records: collect invoices, POs, receipts, payment records, and vendor master data.
- Verify invoices against POs and receipts: confirm 2- and 3-way matches.
- Check approvals and authorizations: ensure each payment followed policy and segregation of duties.
- Test for duplicates and errors: search for repeated invoice numbers, amounts, and vendors.
- Validate vendors: confirm each is legitimate and properly onboarded, with no fictitious entries.
- Reconcile to the general ledger: tie AP records to the GL and bank statements.
- Document findings and act: record discrepancies, recommend fixes, and follow up.
The accounts payable audit checklist: 4 internal controls
Beyond the step-by-step process, a strong internal AP audit evaluates four categories of control. Use these as your checklist.
1. Obligations-to-pay controls
The first line of defense against fraud and error, ensuring payments go to the right vendors. It covers PO approval (authorization before purchase), invoice approval (verifying accuracy and separating approval from payment), three-way matching (invoice vs PO vs receipt), and duplicate-payment searches.
2. Data entry controls
These ensure information entered into the system is accurate, complete, and consistent, since inaccurate data drives improper payments and fraud. Auditors verify entry accuracy and run periodic reviews for errors and discrepancies.
3. Payment controls
The most critical category: making payments accurate, timely, and secure. Key controls are segregation of duties (separating who initiates, approves, and reconciles payments), monitoring for unusual patterns, and securing payment systems and access.
4. Fraud controls
Targeted at vendor-payment fraud, such as false or inflated invoices. Controls include thorough vendor vetting (licenses, tax records), multi-person sign-off on invoices and payments, and ongoing reconciliation of invoice numbers, dates, and amounts against bank statements.
Common accounts payable audit mistakes
A few recurring mistakes undermine otherwise good audits. Watch for these:
- Auditing too infrequently, so problems compound between reviews
- Weak segregation of duties, letting one person both approve and pay
- Skipping vendor validation, leaving room for fictitious-vendor schemes
- Relying on manual spreadsheets, which obscure duplicates and slow the whole review
How AP automation strengthens audits
Manual audits are slow and error-prone because the evidence is scattered across spreadsheets, emails, and filing systems. AP automation software changes that by building the controls into the workflow itself.
- Centralized data: invoices, approvals, and payments in one place, so auditors can trace any transaction
- Approval workflows: rule-based, multi-level approvals enforce policy automatically
- Audit trail: every action logged and timestamped for instant traceability
- Real-time monitoring: discrepancies and anomalies surface as they happen, not months later
- Reporting: comprehensive reports give auditors an instant overview of the AP process
This is what DOKKA’s AP automation is built for: documents are automatically captured, categorized, and validated; compliance rules and approval hierarchies are enforced at every stage; and audits that once took weeks can be completed in days. To see it on your own data, book a quick demo.
Accounts payable audit FAQ
How often should you conduct an internal accounts payable audit?
At least once a year to keep records accurate and catch discrepancies. Audit more frequently after a change in accounting systems or processes, significant operational changes, or whenever fraud or errors are identified, in which case audit immediately to prevent recurrence.
Should you hire an external audit company?
Internal audits are cheaper and benefit from the team’s intimate knowledge of your systems, but can lack objectivity and specialized expertise. External auditors are independent and impartial, lending more credibility and a fresh perspective, but cost more and take longer. Many organizations use internal audits regularly and external audits periodically.
What is the difference between an AP audit and AP automation?
An AP audit is the review process itself; AP automation is the software that runs the underlying workflow. Automation doesn’t replace the audit — it makes auditing faster and more reliable by enforcing controls and producing a complete audit trail. Related reading: preventing accounts payable fraud.
