Invoice fraud detection: Stop duplicate & fake invoices

Your accounts payable team processes hundreds of invoices a week, and every one of them is a potential entry point for fraud. A slightly altered bank account number, a duplicate invoice number, a vendor that doesn't quite exist: any of these can slip past a busy AP clerk and turn into a wire transfer you never get back.

According to the 2026 AFP Payments Fraud and Control Survey, 76% of organizations experienced attempted or actual payments fraud in 2025, with invoice and vendor impersonation schemes among the most common tactics behind it.

This guide walks you through what invoice fraud detection actually involves, the most common schemes to watch for, and a practical, step-by-step process for catching fraudulent invoices before they get paid.

Key takeaways

• Invoice fraud detection combines manual verification controls with AI-powered software that flags duplicates, altered documents, and mismatched data automatically.
• The most common schemes are duplicate invoices, fake vendor invoices, and overbilling from legitimate suppliers.
• Manual review alone can't keep pace with high invoice volumes; automated matching and document forensics catch what human reviewers miss.
• Two-way and three-way matching against purchase orders and goods receipts closes one of the biggest gaps fraudsters exploit.
• Software with duplicate detection, metadata inspection, and image manipulation analysis gives you evidence, not just suspicion, when an invoice looks wrong.
• Generative AI lets fraudsters create convincing fake invoices from scratch, so detection needs to screen for synthetic content, not just edits to real documents.

What is invoice fraud detection?

Invoice fraud detection is the process of identifying invoices that are fake, duplicated, or altered before they're approved for payment. It combines document verification, data matching against purchase orders and vendor records, and pattern analysis to flag anomalies that a manual review would likely miss.

Common types of invoice fraud

Fraud schemes targeting your AP process fall into three categories, and each one leaves a different trail for detection software to catch. Recognizing the pattern behind each one makes it much easier to build the right controls against it.

Duplicate invoices

The same invoice gets submitted more than once, sometimes with a slightly changed invoice number or date to avoid triggering your system's duplicate check. In high-volume AP departments, these can slip through if your only defense is a human scanning invoice numbers.

Fake vendor invoices

Fraudsters create invoices for goods or services that were never ordered, closely mimicking a real vendor's logo, formatting, and email domain to pass a quick glance. Some go further and set up entirely fake vendor accounts in your system.

Overbilling and inflated charges

A genuine vendor relationship exists, but the invoice amount exceeds what was agreed. This might mean inflated quantities, unauthorized price increases, or charges for services that were never delivered. It's harder to catch because the vendor is legitimate, so the invoice draws less scrutiny.

How to detect invoice fraud: Step by step

Hey Doxi, how does Doxis detect invoice fraud?

Why invoice fraud detection matters for your business

Beyond the direct financial loss, a successful invoice fraud incident carries costs that extend well past the transaction itself.

• Direct financial loss: funds sent to a fraudulent account are rarely recovered once they've moved through multiple accounts
• Regulatory exposure: weak financial controls trigger compliance findings, especially in regulated industries
• Vendor relationship damage: disputes over duplicate or fraudulent payments strain legitimate supplier relationships
• Audit and investigation costs: tracing a fraud incident after the fact consumes finance and legal resources
• Reputational harm: repeated incidents signal weak controls to auditors, investors, and partners
• Operational disruption: investigating fraud pulls your AP team away from processing legitimate invoices on time

How to choose the right invoice fraud detection software

Not all invoice processing software is built to catch fraud specifically. When you're evaluating options, look past the OCR accuracy numbers and dig into how the platform actually detects manipulation and anomalies.

Detection depth

Look for a platform that goes beyond duplicate checks to include real document forensics, such as metadata inspection and image manipulation analysis. Without this depth, a manipulated invoice that passes a basic duplicate check will still slip through.

Matching capability

Confirm the software can perform two-way and three-way matching automatically against your ERP data. This closes the gap that fake and inflated invoices rely on most: the absence of a matching purchase order or goods receipt.

ERP integration

Check that it connects natively to your existing systems, SAP included, so flagged invoices don't require manual re-entry. A tool that sits outside your ERP adds a manual handoff step where errors and delays creep in.

Workflow routing

Verify that flagged invoices route automatically to the right reviewer with context attached, not just a generic alert. This keeps your finance team acting on specifics instead of re-investigating each flag from scratch.

Audit trail quality

Make sure the platform logs every validation step and decision for compliance and investigation purposes. A thin audit trail leaves you exposed during a fraud investigation or a compliance review.

Scalability

Check whether the platform handles your invoice volume today and as your business grows, without slowing down approvals. Software that can't scale becomes a bottleneck exactly when your invoice volume, and your fraud exposure, is growing fastest.

Protect your AP process with Doxis

Manual invoice review can't scale with your invoice volume, and that gap is exactly where fraud gets through. Doxis brings document fraud detection directly into your invoice processing workflow, so suspicious invoices get flagged before they're ever approved for payment.

Doxis screens every invoice for duplicates, manipulation, and AI-generated content using copy-move analysis, EXIF metadata inspection, and two-way and three-way matching against purchase orders and goods receipts.

This works across every channel your invoices arrive through and connects natively to the ERP and content systems you already run, including SAP, Salesforce, and Microsoft.

For SAP environments specifically, Doxis Invoice Automation for SAP brings this fraud detection directly into your SAP workflow as part of the broader Doxis Purchase-to-Pay for SAP bundle, covering the full process from requisition through archiving.

Here's what that means for your business:

• Automated duplicate, manipulation, and AI-generated content detection across every invoice channel: paper, email, EDI, and e-invoices
• Document forensics that catch manipulated invoices manual review would miss
• Two-way and three-way matching, whether your invoices run through SAP, another ERP, or a separate AP workflow
• Up to 60-80% lower invoice processing costs alongside stronger fraud controls
• A full audit trail for every flagged invoice and reviewer decision
• Modular architecture that scales from a single fraud-detection use case to your full purchase-to-pay process

Doxis is recognized as a Leader in the Gartner® Magic Quadrant™ for Document Management, reflecting the strength of its intelligent content automation platform across compliance, integration, and AI-powered processing.

Request a free demo below to see how Doxis catches fraudulent invoices before they reach your payment run.

FAQs on invoice fraud detection