Invoice Fraud: How Businesses Can Detect, Prevent & Stop Fake Invoices

Invoice fraud is a growing financial threat that costs businesses millions annually. Fraudsters exploit fake invoices, invoice manipulation, and manual AP system vulnerabilities. Learn how automated invoice processing prevents billing fraud by improving verification, detecting duplicates, and stopping unauthorised payments. Strengthen your business security with these expert fraud prevention strategies.

What Is Invoice Fraud?

Invoice fraud is a deceptive financial crime where fraudsters trick businesses into paying fraudulent invoices by impersonating vendors or manipulating billing details. These scams often involve fake invoices, invoice manipulation, or unauthorized changes to payment details.

According to UK Finance, businesses in the UK lose approximately £93 million (€100 million) annually due to fraud.

• 43% of UK businesses are unaware of the risks of billing fraud.
• More than 3,000 invoice and bank mandate fraud incidents were reported in 2022.
• Billing fraud accounts for 55% of all financial losses from business-related fraud.

Globally, billing fraud has escalated to a $26 billion problem, according to the FBI Internet Crime Report 2023, which recorded 21,832 cases of Business Email Compromise (BEC) linked to invoice fraud in the U.S.

Why Invoice Fraud Is Increasing

• Over 75% of businesses process invoices digitally, increasing exposure to cyber threats (Statista).
• Email phishing and business email compromise (BEC) remain the leading entry points for invoice fraud.
• Remote work has weakened financial controls, leading to a 500% rise in cyber fraud attacks targeting finance departments.

Common Types of Invoice Fraud

Fake Invoice Fraud

A fake invoice is an unauthorized billing document requesting payment for goods or services that were never delivered. These invoices often replicate real supplier invoices, making them difficult to detect.

• 62% of businesses have received a fake invoice in the past year.

Invoice Manipulation Fraud

Invoice manipulation fraud occurs when fraudsters alter legitimate invoices before they reach the finance team. This can involve:

• Changing bank details to reroute funds.

• Inflating invoice amounts to overcharge the company.

• Modifying invoice numbers to bypass duplicate payment detection.

• 40% of financial fraud cases in businesses involve invoice manipulation.

Duplicate Invoice 

Fraudsters submit multiple invoices for the same goods or services, hoping that a company’s manual AP system does not catch the duplicate.

• Duplicate billing fraud costs companies an average of 5% of total revenue annually.

CEO Fraud (Business Email Compromise, BEC)

Scammers impersonate executives, often through email, and pressure employees into making urgent invoice payments.

• CEO fraud resulted in $2.7 billion in global business losses in 2023.

Warning Signs of Invoice Fraud

• Unexpected changes to supplier bank details.
• Urgent or unusual payment requests.
• Duplicate invoices submitted with slight variations.
• Invoices from unverified suppliers.
• Spelling mistakes, vague descriptions, or formatting inconsistencies.

Businesses that rely on manual invoice processing are significantly more vulnerable to these fraud tactics. A report found that companies using manual AP processes are three times more likely to experience invoice fraud.

How Manual AP Processes Enable Invoice Fraud

Many businesses still rely on manual accounts payable (AP) systems, which expose them to significant fraud risks. Fraudsters exploit gaps in traditional invoicing procedures, taking advantage of slow processing times, human error, and limited oversight. Below are key vulnerabilities that make businesses more susceptible to invoice fraud:

Lack of Real-Time Verification

Manual AP systems lack instant verification processes, leaving businesses vulnerable to fraudulent invoices. Without automated cross-checking, companies often fail to detect subtle discrepancies, such as:

• Slight alterations in supplier names or banking details used in fraud schemes.
• Invoices from non-approved vendors slipping through without verification.
• Fabricated purchase orders (POs) or goods received notes (GRNs) going unnoticed due to inefficient record-keeping.

By the time fraud is identified, payments have already been processed, making recovery difficult.

Weak Approval Controls

In a manual invoice processing system, approvals often depend on human oversight, which can be inconsistent and prone to manipulation. Without strict validation procedures, businesses face:

• Invoices being approved without adequate scrutiny, particularly under time pressure.
• Lack of role-based access, enabling unauthorized employees to process payments.
• Single-person approval chains, increasing the risk of internal fraud or collusion.

Fraudsters exploit these weaknesses, often submitting urgent payment requests that bypass proper verification.

No Automated Duplicate Detection

Without an automated invoice processing system, businesses struggle to detect duplicate invoices. Fraudsters can manipulate this by:

• Submitting the same invoice multiple times, with minor changes to invoice numbers or dates.
• Sending invoices to different departments, assuming that separate teams will process them independently.
• Resubmitting previously paid invoices, banking on the finance team’s lack of centralized tracking.

Since duplicate invoices may not be flagged in a manual system, companies can unknowingly pay the same fraudulent invoice multiple times.

Limited Audit Trails

A lack of comprehensive digital records makes investigating fraudulent transactions significantly more challenging. Manual AP processes suffer from:

• Scattered or missing documentation, making it difficult to verify past transactions.
• No clear approval history, making it hard to determine who authorized a payment.
• Inefficient tracking of vendor changes, such as bank account modifications.

Without a detailed and easily accessible audit trail, businesses struggle to pinpoint fraudulent activities, delaying detection and complicating fraud investigations.

How Automated Invoice Processing Prevents Invoice Fraud

Automated AP software is the most effective way to reduce fraud risks.

Key Benefits of Automated Invoice Processing:

• AI-powered invoice verification – Cross-checks invoices, purchase orders (POs), and goods received notes (GRNs).

• Automated bank account validation – Prevents payments to unregistered or changed accounts.

• Real-time fraud detection – Identifies duplicate invoices and altered details instantly.

• Supplier self-service portals – Reduces fraud risk by allowing suppliers to track invoices.

• Strong audit and approval controls – Multi-factor authentication (MFA) prevents unauthorized approvals.

Kefron AP provides real-time fraud prevention by ensuring only legitimate invoices are approved for payment.

More details on how Kefron AP prevents billing fraud can be found here.

Best Practices to Prevent Invoice Fraud

• Adopt AP automation – Reduces fraud risk by 90% (Forrester Research).
• Verify supplier bank details – Confirm changes directly by phone.
• Educate finance teams – 74% of fraud cases occur due to human error.
• Monitor AP transactions with AI tools – Detects unusual payment patterns.

Final Thoughts

Invoice fraud remains a major financial risk for businesses. With fraud tactics becoming more sophisticated, relying on manual invoice processing increases the likelihood of falling victim to fraud. Implementing automated invoice processing solutions significantly enhances security, fraud detection, and compliance.

To protect against fake invoices, invoice manipulation fraud, and duplicate billing fraud, companies should transition to an AP automation system.