How to Spot a Scam on an Invoice

Invoice fraud is one of the fastest-growing financial crimes in the UK. According to UK Finance, authorised push payment (APP) fraud — where victims are tricked into sending money to criminals — exceeded £450 million in 2024 alone. A significant proportion of this involves fake or intercepted invoices.

How invoice scams work

Criminals use several tactics to exploit invoice payments:

Email interception — Fraudsters hack into email accounts of legitimate businesses and monitor conversations. When an invoice is due, they send a convincing email with altered bank details, directing payment to their own account.

Fake invoices — Scammers send invoices that look genuine, often mimicking real suppliers, using copied logos, similar email addresses, and realistic formatting. The bank details, however, belong to the fraudster.

Mandate fraud — A criminal contacts you pretending to be an existing supplier, claiming their bank details have changed. They provide "updated" account information and ask you to redirect future payments.

Red flags to watch for

Here are the key warning signs that an invoice might be fraudulent:

• Changed bank details — If a supplier suddenly asks you to pay into a different account, always verify this by calling them on a known number (not one from the email).
• Pressure to pay urgently — Scammers create a false sense of urgency, claiming late fees or service disruption.
• Slight differences in email addresses — Look closely. A scammer might use "accounts@compny.co.uk" instead of "accounts@company.co.uk".
• Poor formatting or spelling errors — While not always present, grammatical mistakes can indicate a fake invoice.
• Unfamiliar payment references — If the reference number doesn't match your records, investigate further.
• No VAT number, or an invalid one — Legitimate UK businesses registered for VAT will display a valid VAT number. You can check this with HMRC.

What the stats tell us

• £450 million+ lost to APP fraud in the UK in 2024 (UK Finance Annual Fraud Report 2025)
• Purchase scams accounted for £87.1 million of APP fraud losses
• Only 59% of APP fraud losses were reimbursed to victims in 2024
• 71% of scam victims don't report the crime (CIFAS/GASA 2024)

How to protect yourself

1. Always verify bank details — Before making any payment, especially a large one, call the supplier on a number you already have (not one from the invoice) to confirm the account details.
2. Check the company — Verify the company exists on Companies House and that their details match. Check their VAT number with HMRC.
3. Use Confirmation of Payee — This bank service checks whether the name on the account matches who you think you're paying.
4. Don't rush — Legitimate businesses won't pressure you into immediate payment. Take time to verify.
5. Report anything suspicious — Contact Action Fraud on 0300 123 2040.

Run a check before you pay

Before sending any payment based on an invoice, run a quick verification check. WhoAmIPaying checks the bank account name against the payee, verifies the company on Companies House, validates their VAT number with HMRC, and searches online reviews — all in under 30 seconds.

Run a free check now →

It takes less than a minute and could save you thousands.