Why your bank asks for source of funds, ownership and KYC updates

Banks do not finish customer due diligence when the account opens. UK anti-money-laundering rules require ongoing monitoring, so a bank can ask a business to refresh ownership, activity and source-of-funds information when the relationship or transaction pattern changes.

Customer due diligence is about identity, purpose and expected activity

Current HMRC anti-money-laundering guidance describes customer due diligence, often called KYC, as the checks used to understand the customer, beneficial owners and the risk associated with the relationship. The Money Laundering Regulations require relevant firms to identify and verify customers and understand the purpose and intended nature of the relationship.

For a business bank account, that can mean explaining what the company does, who owns and controls it, where customers are located, what typical payments look like and why the account is needed. The bank uses that information as the baseline against which future activity can be assessed.

Keep directors, owners and people with significant control up to date

Corporate customer due diligence includes understanding the ownership and control structure. HMRC's July 2026 guidance specifically says ongoing monitoring should include reviewing beneficial ownership for corporate clients to ensure it remains accurate.

If a shareholder sells a major stake, a new holding company is inserted, directors move abroad or the business is acquired, update the bank rather than waiting for a review to expose outdated records. Companies House changes do not always mean every banking system updates automatically. Keep the bank's ownership information consistent with legal records.

Source of funds means where the money for a particular transaction or relationship comes from

HMRC guidance distinguishes source of funds from source of wealth. Source of funds concerns the origin of money being used in a relationship or transaction, while source of wealth concerns how the customer's wider wealth was accumulated. A bank may ask for source-of-funds evidence where the risk assessment or transaction pattern makes it necessary.

If a company receives £500,000 from a property sale, evidence could include the sale agreement, solicitor completion statement and bank trail. If £300,000 arrives as shareholder funding, the bank may ask about the shareholder, purpose of the funding and evidence showing how the transfer was generated. The answer should connect the transaction to a plausible commercial event.

Large, unusual or changed activity can trigger a fresh review

The Money Laundering Regulations require ongoing monitoring of transactions to check that activity remains consistent with what the firm knows about the customer and its risk profile. HMRC's current guidance identifies triggers such as changes in customer circumstances, unusual transactions and doubts about previously obtained information.

A business that historically receives domestic payments of £5,000 to £20,000 may therefore receive questions after a first £900,000 overseas transfer. That does not mean the transaction is automatically suspicious. It means the activity is outside the previous pattern and the bank may need enough evidence to understand it.

Respond with a coherent evidence pack rather than unrelated documents

HMRC guidance says source-of-funds work is not merely collecting documents; firms should consider whether the explanation and evidence make sense. Businesses should take the same approach when responding to their bank. Explain the transaction in one short narrative, then attach the documents that prove each step.

For an acquisition, that might include the purchase agreement, board approval, loan documentation and the bank trail. For export revenue, provide the contract, invoice and shipping or service evidence where relevant. Avoid sending dozens of unexplained files that force the reviewer to reconstruct the transaction independently.

Reduce future disruption by keeping the bank profile and internal records current

Review the business description, expected turnover, countries of operation and ownership whenever the company changes materially. Keep major contracts, investment documents and transaction evidence in an organised finance archive. This shortens the response time when a bank asks a legitimate question.

For unusual planned transactions, consider telling the bank or relationship manager in advance where the provider offers that route. A large acquisition payment or capital injection can be easier to review when the bank understands it before the transaction appears. The goal is not to avoid KYC. It is to make legitimate activity easy to explain without stopping normal operations for longer than necessary.

Create a small compliance folder that contains the latest ownership chart, Companies House information, major funding agreements, recent accounts and evidence for material capital events. Review it whenever ownership or the business model changes. The value is not only regulatory: the same pack can speed lender applications, audit work and due diligence from major commercial partners.