Cash-Intensive Clients: AML Risk Guide for Accountants Using HMRC Guidance

Cash is still part of everyday business for many accountancy clients, from restaurants and barbers to car washes and market traders. It is also one of the oldest tools of money laundering. HMRC's guidance for accountancy service providers lists cash and cash-intensive customers as one of the risks that firms must consider. This guide draws on the HMRC page Risks common to accountancy service providers, which shows an update date of 9 January 2026, and explains how to turn it into practical checks. Read the HMRC page directly for the full wording.

What HMRC says about cash

HMRC lists services paid in cash or cash-intensive customers as one of the risks common to accountancy service providers. In its words, criminals like using cash because it provides anonymity and is harder to track. The guidance makes the following points.

• Cash deposited directly into your own business bank account from unknown sources raises risk, even if your fees are usually paid online.
• Cash-intensive businesses can be used to pass off illicit funds as legitimate takings.
• Risk rises where the volume of cash does not fit what you know about the business or lacks commercial sense.
• HMRC recommends monitoring cash volumes to check whether your controls still work, and checking that cash payments come from approved customers.

Related warning signs in the same guidance

Cash appears in other items on HMRC's risk list too.

• Significant changes. A move from non-cash to cash transactions, or large shifts in transaction value, is a warning sign.
• Client account activity. Funds paid in from unknown or cash sources, or paid out to a different account, can hide the origin or ownership of money.
• Financial difficulty. Cash-intensive businesses under financial strain may be more vulnerable. HMRC says criminals may buy struggling businesses, sometimes for cash at a price that does not reflect their value, to disguise illicit funds as trading income.

The guidance gives two examples: using a cash-intensive business to mix illicit cash with trading income, and buying a struggling business for cash at an unrealistic price.

Why this matters in 2026

The UK's 2025 national risk assessment, summarised by the AAT, also lists cash-intensive clients among the vulnerabilities of the accountancy sector. HMRC and other supervisors therefore expect to see the point reflected in firms' risk assessments. Our guide to the HMRC sector risk assessment for accountancy service providers sets out how that expectation is framed.

Turning the guidance into controls

HMRC does not prescribe a single method, so the following are practical suggestions you can adapt.

1. Tag cash-intensive clients. Add a field to your client record so that you can see at a glance which clients take significant cash, and build it into the client risk rating.
2. Understand normal. Learn what the business takes in cash, how it is banked and how that compares with sector norms. Your reasonableness test is whether the figures make commercial sense.
3. Compare records with reality. Check takings against purchases, stock, staffing and bank deposits where you can. Incomplete or inconsistent records are a red flag in HMRC's list.
4. Watch for change. Note any shift from card to cash, or a sudden rise in takings, and ask why.
5. Control cash into your own account. Set a firm rule on whether you accept cash fees, and check the source of any unexpected deposit.
6. Consider ownership and control. If the business was recently bought, check who the real owner is and whether the price made sense.
7. Review on a cycle. Apply more frequent reviews to higher-risk cash-intensive clients. Our guide to ongoing monitoring and periodic CDD review explains how to set this up.

When to escalate

If the cash makes no commercial sense, the client cannot explain it, or the explanation does not match your records, escalate to your nominated officer. Whether it amounts to a suspicion that must be reported is a judgement for the officer on the facts, and the firm should record the reasoning either way.

Frequently asked questions

Is every cash-based client high risk?

No. HMRC's guidance treats cash and cash-intensive customers as a risk factor to consider. The overall rating depends on the combination of factors, such as the plausibility of the figures, the client's location and your knowledge of them.

Can I accept cash from a client for my fees?

The guidance warns about unknown cash deposits into your account. Whether you accept cash is a decision for your firm's policy, which should state the controls that apply.

What is the biggest warning sign?

HMRC highlights cash volumes that do not fit what you know about the business or lack commercial sense.

Where is the HMRC guidance?

It is on GOV.UK under Anti-money laundering guidance for the accountancy sector.

Next steps

Run a quick filter on your client list to find those who take significant cash, then check that each has a documented risk rating and a review date. For further training on risk-based AML, explore Learnsignal's CPD courses.