Security & Compliance

Invoice Fraud Prevention: How to Spot and Stop Fake Invoice Scams

Timeline Digital Solutions Team | April 15, 2025 | 14 min read
Invoice Fraud Prevention: How to Spot and Stop Fake Invoice Scams

Between 2013 and 2015, a single scammer tricked Facebook and Google into paying over $100 million in fake invoices. If the biggest tech companies in the world can be fooled, so can you.

Invoice fraud is not about hacking your firewall; it's about hacking your people. It relies on urgency, authority, and the mundane nature of paying bills. This guide will teach you how to spot the red flags and lock down your accounts payable process.

What is Invoice Fraud?

Invoice fraud occurs when a business pays a fraudulent invoice sent by a scammer who is pretending to be a legitimate supplier. The money is sent to the scammer's bank account, and once the transfer clears, the funds are often moved offshore instantly.

It is a low-tech, high-reward crime. All a scammer needs is a PDF editor and an email address.

Common Types of Scams

1. The "Change of Bank Details" Scam

You receive an email from a regular supplier: "Hey, our bank account is under audit, please make this month's payment to our new account." The email looks real. The logo is real. But the bank account belongs to a thief.

2. CEO Fraud (Business Email Compromise)

An email comes from your "CEO" to the finance manager: "I need this invoice paid urgently for a confidential acquisition. Do it now." The urgency makes the employee bypass standard checks.

3. Phantom Vendor

A scammer sends an invoice for a small amount (e.g., $49 for "Domain Hosting" or "Directory Listing"). It's small enough that no one questions it, and it gets paid automatically.

Red Flags to Spot

Train your team to look for these warning signs:

[CONTENT IMAGE 2: Warning sign illustration showing a fake email address vs a real one (typo spotting)]

AI Prompt: Warning sign illustration showing a fake email address vs a real one (typo spotting)

The "Call Back" Rule

The Golden Rule: If a supplier asks to change their bank details via email, NEVER update it without verifying.

Call the supplier using a phone number you already have on file (not the one in the suspicious email). Ask to speak to your contact and confirm the change verbally. 99% of the time, they will tell you they never sent that email.

Internal Controls: The 3-Way Match

The best defense is a boring accounting process called the 3-Way Match.

[CONTENT IMAGE 1: Infographic of the '3-Way Match' process (Purchase Order + Delivery Note + Invoice = Payment)]

AI Prompt: Infographic of the '3-Way Match' process (Purchase Order + Delivery Note + Invoice = Payment)

Before paying an invoice, the accounts payable team must match three documents:

  1. Purchase Order (PO): Did we order this?
  2. Receiving Report (Delivery Note): Did it actually arrive?
  3. Invoice: Does the price match the PO?

If you don't have all three, the check doesn't get signed.

Technology Solutions

Humans make mistakes; software doesn't. AP Automation tools can help:

What to Do If You Pay a Fake Invoice

Speed is critical.

  1. Call Your Bank Immediately: Ask them to recall the wire transfer. If caught within hours, it might be reversible.
  2. Contact the Receiving Bank: Alert the bank where the money was sent that the account is being used for fraud.
  3. File a Police Report: You will need this for insurance claims.
  4. Audit Your Email: If the scammer knew your supplier's details, your email system might be compromised. Change passwords immediately.

Training Your Team

Your Accounts Payable clerk is the goalkeeper. They need to feel empowered to say "No" to the CEO (or the fake CEO) if the process isn't followed.

Run phishing simulations. Send fake "urgent" emails to your staff and see who clicks. Use it as a teaching moment, not a punishment.

Legal Recourse

Can you get the money back? Often, no. Banks are generally not liable if you authorized the payment, even if you were tricked.

However, "Cyber Insurance" or "Crime Insurance" policies may cover social engineering fraud. Check your policy today—standard liability insurance usually excludes this.

Frequently Asked Questions

1. What is "Whaling"?

Whaling is a specific type of phishing attack that targets high-profile executives ("big fish") like the CEO or CFO to steal sensitive data or authorize payments.

2. Are paper invoices safer?

Not necessarily. Anyone can print a fake invoice and mail it. However, digital fraud is more common because it's easier to scale.

3. How do scammers get my supplier's info?

They might hack your supplier's email, hack your email, or simply look at your website's "Our Partners" page and guess.

4. Should I put my bank details on my invoices?

Yes, you have to so clients can pay you. But warn clients that you will never change these details via email.

5. What is "Social Engineering"?

It's the psychological manipulation of people into performing actions or divulging confidential information. It's "hacking the human."

6. Can small businesses be targeted?

Yes. Small businesses are often easier targets because they have fewer security controls than large corporations.

7. Does 2-Factor Authentication (2FA) help?

2FA protects your email from being hacked, which prevents scammers from reading your correspondence to craft convincing fake invoices.

8. What is a "Mule Account"?

A bank account owned by a third party (often unknowingly) used to receive stolen funds and transfer them to the criminal, obscuring the trail.

9. How often should I audit my vendor list?

At least annually. Remove inactive vendors to prevent "dormant vendor" fraud where employees or hackers reactivate old accounts to pay themselves.

10. Is PayPal safer than bank transfer?

PayPal offers some buyer protection, but for B2B transactions, bank transfers are standard. The key is verifying the destination account.

11. Can AI detect fraud?

Yes, modern accounting software uses AI to spot anomalies, like a sudden spike in invoice value or invoices sent on weekends.

12. What is "Invoice Padding"?

This is when a real supplier adds extra items or inflates prices on a genuine invoice, hoping you won't notice. It's fraud, but from a legitimate source.

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