Supplier Bank Details Changed? A Weekend Payment-Control Check for Construction Directors

A supplier asks you to update its bank details before Monday’s payment run. The invoice relates to genuine work, the name is familiar and the money is due. None of that, by itself, proves that the new account is the right destination.

For construction limited companies turning over more than £1 million across Sheffield, Rotherham, Barnsley and Doncaster, a misdirected payment can leave less cash available for wages, materials and the next subcontractor run. This Saturday’s useful job is not another cash-flow forecast. It is checking who can change the destination of money you have already agreed to pay.

Check the destination, not just the invoice

The National Cyber Security Centre’s business payment fraud guidance explains that criminals can impersonate familiar contacts and ask for money to be paid into a different account. This is sometimes called business email compromise. A convincing email thread is therefore not enough to approve a change.

Keep three questions separate: is the work payable, is the request genuinely authorised by the supplier, and is this the supplier’s authorised receiving account? VAT invoice checks and Construction Industry Scheme checks have different purposes. CIS verification is not a bank-ownership check. Passing a tax check must not become permission to skip payment-destination verification.

Legitimate changes happen. A supplier might switch banks or use an authorised finance arrangement. Your process should establish the supplier’s identity and authority for the receiving account, rather than automatically rejecting every unfamiliar account name. Friday afternoon is not an authentication method.

Make an independent call before changing the record

Start with contact details you held before the request arrived. Call a known supplier contact using that established number, not the number in the change email, its attachment or its signature. Do not treat replying to the same email as independent verification.

The NHS Counter Fraud Authority’s invoice and mandate fraud guidance recommends checking supplier changes through established contact details already on file. It also warns that those existing details may themselves have been recently changed. These are useful controls to adapt for construction businesses, rather than construction-specific legal requirements.

Ask the known contact to confirm that the change is authorised, the account holder’s name, the sort code and account number, and when the change takes effect. Where someone else will receive payment, confirm the arrangement with the supplier through that independent route. If you cannot establish a reliable contact, hold the amendment while you resolve it. A letter or screenshot can support the record, but should not replace the independent check.

Keep a short change log: supplier, previous and proposed details, request date, who was contacted, which established number was used, what was confirmed, and who checked it. Restrict access because it contains banking information. Record the check while it is fresh, not from memory after the payment run.

Give amendment approval and payment release different jobs

Wherever possible, separate the person who edits supplier bank details from the person who approves the amendment and releases payment. The NHS guidance supports separating duties and controlling access to payment systems. In practice, your company might have an accounts colleague enter the change, a director approve the evidence, and an authorised payment approver review the final run.

The payment approver needs more than a total and a familiar supplier name. Show which accounts changed, the verification record and the actual destination being paid. Check the final bank payment instructions against the approved record, not only the accounting-system summary. If a destination changes after approval, require fresh approval before release.

This protects the team as well as the bank balance. Make pausing an unverified change normal, even when a director asks for speed. The rule should apply to everyone, without suggesting that the accounts team has done anything wrong.

Plan for absence before it becomes an exception

Small finance teams cannot always achieve perfect separation. Agree named cover in advance, with individual logins and a written record of who may approve what. Avoid solving absence by sharing a director’s credentials.

For a genuine exception, keep independent supplier verification, record why normal cover is unavailable, and have a named director check the evidence and destination before release. Arrange a separate retrospective check when cover returns. If that minimum cannot be met, hold the affected payment and discuss timing with the supplier through the known contact. This is a proposed company control, not a claim that every business must follow one prescribed procedure.

Three Actions to Take Next Week

1. Trace one recent bank-detail change. Follow it from request to supplier record to bank payment. Check whether independent verification and approval are recorded; use any gap to improve the process, not assign blame.
2. Add a changed-account check to the payment run. Give the approver the destination and verification evidence, and require fresh approval for any subsequent destination change.
3. Write the absence arrangement. Name the backup approver, define the minimum checks for an exception and agree who checks it afterwards. Make clear that nobody must share login details.

If something looks wrong, act promptly

Pause the affected amendment or payment. If money may have gone to a fraudulent account, contact your bank promptly through its verified official contact details and alert your IT support where email compromise is suspected. Preserve the emails, change record and payment details. The GOV.UK reporting guidance identifies Report Fraud as the reporting route for fraud and cyber crime. Reporting is not a guarantee of recovering money.

If you would like to strengthen payment controls alongside your construction accounts, book a consultation with Tax by Sterling.

Could your next payment approver clearly explain how a changed supplier account was verified?