Troubleshooting

Fake Invoice Scam - Warning Signs to Watch For

Learn to spot fake invoice scams targeting your AP department. Identify red flags, protect your company, and know what to do if you receive a fraudulent invoice.

3 min read · Updated February 2026

Fake Invoice Scam: Warning Signs to Watch For

Invoice fraud costs businesses billions of dollars every year. Scammers know that busy AP departments process hundreds of invoices monthly, and they’re betting you won’t scrutinize every single one. Here’s how to spot fake invoices before they cost your company money.

How Fake Invoice Scams Work

Fraudsters send invoices for goods or services that were never ordered, never delivered, or don’t exist. They rely on a few key tactics:

  1. Volume camouflage: Send invoices that look routine and blend in with legitimate ones
  2. Authority exploitation: Impersonate known vendors or reference real employees
  3. Urgency pressure: Create time pressure with “past due” notices or late fee threats
  4. Small amounts: Keep amounts low enough to avoid extra scrutiny

Red Flags to Watch For

1. You Don’t Recognize the Vendor

The most obvious sign—you’ve never heard of this company. But scammers are smart. They’ll use names similar to your actual vendors:

  • “Microsoft Services LLC” instead of “Microsoft Corporation”
  • “Amazon Web Svcs” instead of “Amazon Web Services”
  • Adding “Inc” or “LLC” to a vendor that’s actually a sole proprietor

What to do: Before paying any invoice from an unfamiliar vendor, verify they’re in your vendor master file with matching details.

2. Generic or Vague Descriptions

Legitimate invoices describe specific goods or services. Fake ones use vague language:

  • “Consulting services - Q4”
  • “Annual maintenance fee”
  • “Professional services rendered”
  • “Supplies”

What to do: Request a detailed breakdown of what was provided, including dates, quantities, and specific deliverables.

3. Missing or Incorrect Details

Fake invoices often have subtle errors:

  • Wrong company name or address
  • Missing or incorrect PO number
  • Tax ID that doesn’t match your records
  • Invoice number format that differs from previous invoices

What to do: Compare every element against the vendor’s existing records in your system.

4. Pressure Tactics

Scammers create urgency to bypass your normal review process:

  • “PAST DUE - Pay immediately to avoid service interruption”
  • “FINAL NOTICE - Account will be sent to collections”
  • “Pay within 24 hours to avoid late fees”
  • Phone calls demanding immediate payment

What to do: Never let urgency override your verification process. Legitimate vendors will understand a brief delay for verification.

5. Unusual Payment Instructions

Watch for requests that deviate from normal payment methods:

  • “We’ve changed our bank account” (classic BEC scam)
  • “Please wire payment instead of ACH”
  • “Pay via gift cards” (always a scam)
  • Payment to a different entity than the invoice sender

What to do: Verify any banking changes through a known phone number—not the one on the suspicious invoice.

6. Round Dollar Amounts

Real invoices typically have specific amounts based on actual goods, services, and taxes:

  • Legitimate: $4,847.23
  • Suspicious: $5,000.00

What to do: Round amounts aren’t always fraud, but they warrant extra scrutiny.

7. Poor Quality or Formatting Issues

Fake invoices often have telltale quality issues:

  • Blurry or low-resolution logos
  • Inconsistent fonts or spacing
  • Spelling or grammar errors
  • Generic templates that don’t match the vendor’s brand

What to do: Compare against previous legitimate invoices from the same vendor.

8. Domain Doesn’t Match

The email sender’s domain should match the vendor’s official domain:

What to do: Hover over email addresses to see the actual domain. Check for lookalike characters.

Common Fake Invoice Schemes

The Directory Scam

You receive an invoice for a “business directory listing” or “domain renewal” you never requested. These often target new businesses or use domains that sound official.

The Office Supply Scam

Invoices for toner, paper, or cleaning supplies that were never ordered. Scammers call to “confirm an order” then send an invoice claiming you approved it.

The Vendor Impersonation

Scammers research your real vendors and send invoices that look nearly identical to legitimate ones, sometimes with just the payment details changed.

The Executive Impersonation (BEC)

An email appearing to be from your CEO or CFO requesting urgent payment to a new vendor. The email address is spoofed or uses a lookalike domain.

What to Do If You Receive a Suspicious Invoice

1. Don’t Pay It

This seems obvious, but pressure tactics work. Take a breath and follow your process.

2. Verify Independently

Contact the vendor using contact information from your records—not from the suspicious invoice. Confirm:

  • Did they send this invoice?
  • Is this their current banking information?
  • Does this invoice match a real order or contract?

3. Document Everything

Save the suspicious invoice and any related emails. Note:

  • How it was received
  • What made you suspicious
  • Who you contacted to verify
  • The outcome

4. Report It

  • Report to your IT security team
  • Report to the FTC at reportfraud.ftc.gov
  • If it impersonates a real company, notify that company

5. Alert Your Team

Share the attempted scam with colleagues so they know what to watch for.

Building Defenses Against Invoice Fraud

Implement Three-Way Matching

Require a matching purchase order and receiving document before paying any invoice. This single control stops most fake invoices.

Verify All Vendor Changes

Any change to vendor banking information should trigger a verification call using a known phone number.

Segregate Duties

The person who approves vendors shouldn’t be the same person who approves payments.

Control Your Invoice Intake

When invoices arrive from dozens of different email addresses and sources, spotting fakes becomes nearly impossible. A controlled submission process creates a single point of entry where you can apply consistent verification.

Train Your Team

Regular training helps AP staff stay alert to evolving scam tactics. Include real examples of attempted fraud.

Key Takeaways

  • If you don’t recognize the vendor, verify before paying
  • Vague descriptions and pressure tactics are major red flags
  • Always verify banking changes through known contact methods
  • Control your invoice intake to create consistent verification
  • Document and report attempted fraud to help stop scammers

Want a controlled front door for all vendor invoices? See how BillerPlus prevents unauthorized submissions →

Tired of invoice chaos?

BillerPlus gives you a single, controlled front-door for all vendor invoices. No more email hunting.

Start free trial

More in Troubleshooting