Cash deposits and AML controls: know where large business cash deposits came from

Cash entering a business bank account can be legitimate sales revenue, but cash is harder to trace than an electronic customer payment. Businesses in regulated sectors and cash-heavy industries need records that explain who generated the money, where it was collected and why the deposit pattern matches the company's normal activity.

Cash deposits can create elevated money-laundering risk

HMRC's current AML guidance for money-service businesses warns that direct cash deposits into a business bank account can pose significant money-laundering risk, especially where multiple people or locations can deposit anonymously. The same practical warning is useful for other cash-heavy businesses even where different regulatory guidance applies.

A bank can also question a sudden change in cash profile under its own ongoing monitoring. A retailer that normally deposits £5,000 a week and suddenly receives £90,000 from several cities should expect questions rather than assuming every cash credit looks like ordinary takings.

Maintain evidence linking cash to the underlying business activity

Use till reports, sales summaries, event records, customer receipts or cash-count sheets to explain where deposits came from. HMRC's July 2026 source-of-funds guidance says verifying source of funds can be required where risk and due diligence make it necessary.

The bank statement shows only that £12,000 cash was deposited. It does not prove whether that money came from three shops, one high-value customer or somebody unrelated to the business. Internal evidence should answer that question.

Control third-party deposits into the company account

Direct cash deposited by customers or agents can bypass the company's own till and cash-count process. Where the business allows it, require a customer or transaction reference and monitor locations and amounts.

Unexpected cash should be investigated, not simply booked as sales. A deposit from an unknown person can create both AML and accounting problems. If regulated AML obligations apply and suspicion remains, follow the business's escalation and Suspicious Activity Report procedures.

Cash collection services do not remove the business's monitoring responsibility

HMRC's risk guidance notes that using third-party cash collectors or van services can make it harder for the business to see the cash and its source. The business still needs procedures that reconcile collected bags or pickups to known takings and deposit credits.

Use sealed-bag identifiers, pickup receipts and bank deposit reports. Differences between till cash, collector receipt and bank credit should be investigated promptly rather than written off as "cash variance".

Prepare to answer bank source-of-funds questions

If the bank asks why cash deposits increased, provide a concise explanation with evidence: new store opening, festival takings, seasonal trading or another commercial event. Do not send only screenshots of the bank balance because the bank already knows the cash arrived.

Where the change is permanent, tell the bank before repeated unusual deposits create account restrictions. Updating expected transaction activity can reduce false alarms and gives the provider a more accurate customer-risk profile.

Set cash thresholds and escalation rules

Define who can deposit cash, maximum till balances, frequency of bank deposits and when unusual cash needs senior review. Separate cash count from deposit preparation where staff numbers allow.

Keep the policy proportional. A café and a wholesale currency business face different risks. The objective is not paperwork for every banknote; it is being able to explain material cash movement and identify patterns that do not match the business.

Create a cash-deposit exception report using three tests: amount, location and depositor. A deposit that is twice the normal daily amount, made 200 miles from the trading site or made by an unknown third party should move into review automatically. The business does not need to treat every unusual item as criminal, but it should be able to explain why it accepted it.

Where several branches deposit to one central account, give each branch a distinct reference or bag series. That allows finance to match physical cash to the correct store and identify missing deposits quickly. Anonymous branch cash makes both AML monitoring and ordinary theft investigation harder.

Retain evidence proportionately. High-volume retailers do not need to preserve a customer identity record for every £10 cash sale, but they should keep till totals, deposit records and explanations for unusual high-value cash. The risk-based objective is to make suspicious patterns visible without making routine trade impossible.

For customer-specific high-value cash, record enough information to connect the deposit to the invoice or contract. A £40,000 cash receipt against a vehicle or wholesale transaction deserves more source-of-funds attention than a day's aggregated retail takings, even when both are legal. Apply the business's risk assessment consistently rather than relying on amount alone.

Escalate bank queries centrally. Several branch managers giving different explanations for the same unusual deposit pattern can create more concern. One finance or compliance owner should gather the evidence, answer the provider and update the expected-account profile where the activity is legitimate and ongoing.