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Guide

A payment verification procedure to stop wire fraud

Most payment fraud is not a technical failure. It is a convincing request that skips a step. A written verification procedure, with callbacks to known numbers, dual approval and a hold on changed banking details, closes the gap.

4 min readCyber Forensics

Reviewed by the ITRS security team · Last updated

Where payment fraud gets in

The Canadian Anti-Fraud Centre collects reports of fraud and cybercrime from across Canada, and business payment fraud follows a few familiar patterns. Each one ends with an employee sending real money to an account the fraudster controls, usually because the request looked routine and urgent at the same time.

  • Vendor impersonation: an email from a supplier, or a look-alike domain, announcing new banking details before the next invoice
  • Compromised mailbox: an attacker inside a real vendor's or your own mailbox replies in an existing thread with altered instructions
  • Executive impersonation: the 'CEO' or 'managing partner' asks for an urgent, confidential transfer, sometimes now using cloned voice or video
  • Payroll diversion: an 'employee' asks HR to update direct-deposit details
  • Closing and settlement fraud: altered payout instructions in real estate, legal or lending transactions

Callback verification

The core control is simple: any new payee, any change to payment details and any unusual request is confirmed by calling the requester on a number you already had, not one supplied in the request.

Write it precisely so it cannot be satisfied by a shortcut:

  1. Use a known number

    From the vendor master file, a signed contract or the vendor's official website, never from the email, invoice or signature block in the request.

  2. Speak to a known person

    Ideally someone you have dealt with before. Ask them to confirm the details read back to them, rather than reading them out yourself.

  3. Record the call

    Who called, whom they spoke to, the number used, date and time, and the result, attached to the payment record.

  4. No reply-to-email confirmation

    Replying 'please confirm' to the same email thread confirms nothing if the thread is compromised.

Dual approval and thresholds

Two people should be needed to release any payment above a threshold that fits your business, and every payment to a new or changed payee regardless of amount. In online banking, set up separate roles so one person creates a payment and another approves it, and make sure the approver sees the destination account, not just the amount.

Set thresholds based on what you could afford to lose, not on what is convenient. Review them yearly, and watch for payments split to stay just under the limit.

Change-of-banking-details process

StepOwnerEvidence
Request received by any channel
Anyone
Forward to accounts payable; never act on it directly
Callback to known number
Accounts payable
Call log entry
Second-person review
Finance lead
Approval in the vendor master change record
Hold period before first payment
Accounts payable
A short cooling-off period set by policy
Confirmation to old contact details
Accounts payable
Notice sent to the vendor's previous contact
Small test payment, if used
Accounts payable
Vendor confirms receipt by phone

Exceptions under pressure

Fraudsters manufacture urgency: a deal closing today, a supplier threatening to stop shipments, a CEO who is 'in a meeting and can't talk'. The procedure has to hold precisely when someone senior asks to skip it.

Put it in writing, signed by leadership, that no one, including the owner, may instruct staff to bypass verification, and that staff who follow the procedure and delay a genuine payment will be backed. Give finance a short script: 'Our policy requires a callback before any change. I'll call you on the number we have on file.'

Payment control questions

No. Long-standing suppliers are exactly who fraudsters impersonate, because their invoices are expected. Most vendors appreciate the check once they understand why.

Testing the control

Controls drift. Every few months, pick a sample of payee changes and check that each has a callback record and a second approval. Run a tabletop with finance on a business email compromise scenario. Include a fake change-of-details request in your phishing simulations for accounts payable.

On the technical side, reduce the number of convincing requests that reach finance at all: MFA on every mailbox, alerts for new forwarding rules, external-sender tagging, and DMARC enforcement so your own domain cannot be spoofed to your vendors. Microsoft's incident response playbooks for phishing and password spray describe how attackers get the mailbox access these frauds depend on.

We investigate payment fraud when it happens and help finance teams design controls that hold up.

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