Business email compromise: how to stop wire transfer fraud in your inbox

Business email compromise has quietly become one of the most expensive forms of online crime. Instead of breaking into systems, criminals study how real companies work, then insert a single convincing email at just the right moment.

The good news is that most of these scams collapse if one person spots something off. With a few clear routines and technical controls, even lean teams can make this crime much harder to pull off.

What business email compromise actually looks like

Business email compromise (often shortened to BEC) is a targeted fraud where criminals impersonate someone you trust, usually to trigger a payment, change bank details or send confidential data. The message often looks ordinary and urgent, not obviously malicious.

Two common patterns appear again and again: an email that asks finance to pay a fake invoice, and a message that quietly changes payment details for a real supplier, so the next genuine invoice goes to a criminal’s bank account.

How criminals get in the middle of real conversations

Attackers do not always hack your mail server directly. In many cases they steal a password through phishing, re-use credentials from a data breach, or log in through a poorly secured personal email that employees use for work tasks.

Once inside any mailbox, they may set up forwarding rules to copy all messages from finance or executives to an external address. Others register lookalike domains, such as swapping one letter in your company name, and rely on rushed staff not noticing the difference.

High‑risk moments that deserve extra scrutiny

While every suspicious message matters, a few types of requests deserve automatic caution. These are the moments where one mistaken click or approval often leads to large losses.

• First‑time payments to a new supplier, contractor or legal firm
• Requests to change bank details, IBAN, routing number or payee name
• Messages that bypass normal approval steps or ask for confidentiality
• Urgent transfers linked to deals, mergers, taxes or penalties
• Instructions that arrive when the sender is traveling or unreachable

Any of these scenarios should trigger a second step of verification that does not rely on email alone.

Human checks that block most BEC scams

Technical tools help, but BEC is largely a people problem. Short, repeatable checks embedded into daily work can make a huge difference for finance, HR and project teams.

• Verify money movement out of band:For payment changes or large transfers, confirm through a known phone number or secure chat, not by replying to the same email thread.
• Use dual approval for higher amounts:Require two people to sign off on transfers above a threshold, ideally from different teams such as finance and operations.
• Standardize how requests arrive:Route payment instructions through a central system or ticket tool. Random emails from executives should raise a flag rather than speed things up.
• Slow down urgent requests:Train staff that “urgent and secret” is a classic fraud pattern. No one should face consequences for pausing a transfer to verify it.

Strengthening email security basics

Attackers rely on easy entry points. A few focused improvements to core email security can block many attempts long before a user sees anything.

• Turn on multifactor authentication:Require a one‑time code, app prompt or hardware key for all mail logins, for every employee and every administrator.
• Review mail forwarding rules:Regularly audit automatic forwarding and redirect rules, especially from finance and executive mailboxes, and remove any that are not clearly needed.
• Use strong spam and phishing filters:Modern cloud mail services include advanced filtering, link scanning and attachment checks that can remove many malicious messages from view.
• Harden your domain:Configure SPF, DKIM and DMARC records so that receiving servers can better detect spoofed messages that pretend to be from your domain.

Training staff without scaring them

Many BEC attempts succeed because employees feel pressure to be fast and helpful. Awareness efforts work best when they support staff in saying “I need to verify this” rather than shaming them for mistakes.

Short, regular sessions with real examples from your industry are more effective than long annual lectures. Encourage people to share near‑misses and unusual messages, and treat early reporting as a positive action.

Incident response when something slips through

Even well prepared organizations sometimes send money to a fraudulent destination. Quick, coordinated action can still limit damage and sometimes recover funds.

• Contact your bank immediately:Ask for a recall or freeze on the transfer, provide transaction details and explain that it is a fraud case.
• Alert your incident response lead:Involve whoever coordinates security issues so they can preserve logs, check for mailbox rules and look for other compromised users.
• Notify partners or clients:If fake invoices or messages went to them in your name, inform them quickly through trusted channels and give clear next steps.
• Review what went wrong:After urgent actions, run a short review to identify missed signals and refine processes or training.

Making BEC a board‑level and finance topic

Because BEC targets money flows and decision makers, it fits naturally into financial controls and governance, not only IT policy. Boards and leadership teams should understand that these scams are a business risk similar to fraud or theft.

Integrate BEC into vendor onboarding, treasury procedures and executive travel plans. When everyone accepts that unusual payment requests must pass through clear checks, a convincing fake email turns from a crisis into an easily caught annoyance.