When a Supplier’s Bank Details Change: A Verification Protocol (2026)

Quick answer. A request to change a supplier’s bank details is the highest-value single point of risk in a supply relationship, because the amount involved is the whole balance of an order. The rule that makes it manageable is simple: verify through a channel you already had, never through the channel the request arrived in.

1. Why this is the highest-value point of risk

• The amount is large. The balance of an order is the single biggest transfer in the relationship, and it is usually made on the strength of a document.
• The pattern is familiar. A message that appears to come from the supplier announces a change of account, with some plausible reason attached.
• It is designed to look routine. The request arrives in the ordinary course of business, often near the point where an invoice is due.
• The consequence is direct. Money transferred to a wrong account is rarely recovered, and the supplier still expects to be paid.

2. The rule that makes it manageable

• Verify through an existing channel. A telephone number or an address you already had, rather than any contact detail contained in the request itself.
• Why that specific rule. A compromised mailbox can supply a false confirmation number — so using anything from the request means the check confirms nothing.
• Two people, separately. A change of account is significant enough to require a second person, contacting through a second existing channel.
• Nothing happens on the strength of an email alone. Which removes the single step the whole pattern depends on.

3. What a verification protocol looks like

• Written and signed. A change request on company letterhead with a signature, in addition to the message.
• Independent callback. To a number from your own records, not from the request.
• Second confirmation. Through a different existing contact, by a different person on your side.
• A test payment. A small amount first, confirmed as received by the supplier before the balance is sent.
• Recorded. Who verified, when, through which channel, and what was said.

4. The counter-intuitive part

• A change on an established account is more dangerous, not less. A familiar relationship is exactly what makes the request credible.
• Timing is part of the pattern. Requests often arrive just before an invoice falls due, when the pressure to pay quickly is greatest.
• Small changes are a test. A slight variation in the account name or the bank details can be a trial before a larger attempt.
• Politeness maintains the appearance. The message is usually courteous and unhurried, which is part of why it works.

5. What to do if a payment has gone to a wrong account

• Contact the bank immediately. Recall is time-sensitive, and the first hours matter more than anything else.
• Notify the supplier through an existing channel. So both sides are working on the same facts rather than on the message.
• Preserve the correspondence. Headers, attachments and timestamps, since they establish what was received and when.
• Report it. To the relevant authority in your jurisdiction and to your own bank’s fraud team.
• Review the controls afterwards. The failure is nearly always a missing independent channel rather than a person being careless.

6. Common errors

• Replying to the request to confirm it. The reply goes to the same place, which confirms nothing.
• Calling the number in the request. The number is part of the request, so the call validates the request rather than the supplier.
• Skipping the check because the relationship is long. The relationship is what makes the request credible.
• Sending the balance first and confirming afterwards. The confirmation is only useful before the transfer.
• Not recording the verification. Without a record, the check cannot be shown to have happened.
• Treating it as an IT problem. It is a payment control problem, and the control is a telephone call to a number you already had.

7. How to compare two suppliers

• Whether they confirm account details in writing at the start. On letterhead, with a signature, before the first payment.
• Whether they have a stated protocol for changes. A supplier with a protocol has thought about the risk.
• Whether they expect a callback. A supplier who questions an unverified change is a better counterparty than one who does not.
• Whether the contracting entity and the account match. Which should be checked at the outset, not only when something changes.
• Whether the protocol is in the contract. Since it is cheapest to agree before the first transfer rather than after the first problem.

Published: 2026-10-15 · Xiamen Unitex Trade Co., Ltd. — OEM & ODM underwear sourcing partner

Unitex Underwear (Xiamen Unitex Trade Co., Ltd.) — OEM/ODM underwear sourcing and supply-chain partner in Xiamen, China; in the trade since 2009, incorporated in 2013. Based in the Xiamen–Quanzhou–Jinjiang knitwear cluster, Fujian Province, south-east China.