Money laundering is the process of making the proceeds of crime appear legitimate. Criminals generate "dirty" money — from fraud, drugs, trafficking, corruption and more — and need to disguise its origin so they can spend, invest or move it without attracting attention. Laundering is the bridge between a crime and the criminal enjoying its rewards. Break the bridge, and you make the underlying crime far less profitable. That is the entire logic of the AML system.
The three stages: placement, layering, integration
The textbook model breaks laundering into three stages. Real cases blur them, but the model is the clearest way to understand what launderers are trying to achieve.
- PlacementDirty cash enters the financial system — deposited, used to buy assets, or fed through a cash-intensive business. This is where the money is most exposed and easiest to detect.
- LayeringThe money is moved through a web of transactions — transfers, shell companies, asset purchases and sales — to obscure the audit trail and break the link to the original crime.
- IntegrationThe now-"clean" money re-enters the legitimate economy as apparently lawful wealth: property, investments, business income the criminal can use openly.
Build the cycle
Put the three classic stages in the order a launderer follows.
- Integration — clean-looking money re-enters the legitimate economy
- Layering — funds are moved through transactions to obscure the trail
- Placement — dirty cash enters the financial system
What the UK law actually says
In the UK, the principal money-laundering offences are in Part 7 of the Proceeds of Crime Act 2002 (POCA). Three core offences matter:
| Section | Offence | In plain terms |
|---|---|---|
| s.327 | Concealing | Concealing, disguising, converting, transferring or removing criminal property |
| s.328 | Arrangements | Entering an arrangement you know/suspect helps another acquire or use criminal property |
| s.329 | Acquisition/use | Acquiring, using or possessing criminal property |
Two features make POCA wide-reaching, per the CPS prosecution guidance:
Failing to report a suspicion, where you work in the regulated sector, can itself be an offence — which is why suspicious activity reports exist. Sentencing follows the Sentencing Council guideline and can be severe.
Real-world typologies
Laundering is not abstract. A few recurring patterns:
| Typology | How it works |
|---|---|
| Cash-intensive front | A legitimate-looking cash business (car wash, restaurant) mixes dirty cash with real takings |
| Shell company layering | Money moves between companies with no real activity to break the trail |
| Trade-based laundering | Over- or under-invoicing of goods moves value across borders disguised as trade |
| Real estate | Property bought (often via companies) to absorb and integrate large sums |
| Money mules | Individuals' accounts used to receive and forward funds, wittingly or not |
How big is the problem?
The scale is genuinely hard to measure — that is the nature of hidden crime — but every serious estimate puts it in the hundreds of billions of pounds globally each year. The FATF, the global standard-setter, exists precisely because laundering crosses borders and needs a coordinated response. The UK's National Crime Agency consistently assesses money laundering as a strategic threat enabling the most serious organised crime.
Why this matters for due diligence
Every due-diligence obligation traces back to this: the regulated sector is the bridge launderers need, so the law makes that sector a line of defence.
- A crime generates dirty moneyThe criminal needs to launder it
- Launderer approaches the regulated sectorYour firm is a potential bridge
- Due diligence, monitoring and reportingThe bridge is closed
A Probitas check supports that defence: it reads a name or company against sanctions, PEP and adverse media sources and anchors what it finds to the public record, so your due-diligence decision rests on evidence. The screen surfaces the risk; the judgement remains yours.
Five questions on the essentials.
Money
What is money laundering in simple terms?
It is making money from crime look legitimate, so the criminal can use it without attracting suspicion. It disguises the origin of "dirty" money through a series of steps until it appears to be clean, lawful wealth.
What are the three stages of money laundering?
Placement (introducing the dirty money into the financial system), layering (moving it through transactions to hide the trail), and integration (the now clean-looking money re-entering the legitimate economy as apparent lawful wealth).
What law makes money laundering illegal in the UK?
The Proceeds of Crime Act 2002 (POCA), Part 7, contains the principal offences — concealing (s.327), arrangements (s.328) and acquisition, use or possession (s.329). The Money Laundering Regulations 2017 set the preventative duties for regulated firms.
Is there a minimum amount for money laundering?
No. POCA has no de minimis threshold. A small amount of criminal property is still criminal property, and small-scale laundering is still an offence.
How is money laundering connected to due diligence?
Launderers need legitimate businesses — banks, lawyers, accountants, agents — to move and disguise money. AML due diligence makes those regulated firms a line of defence, so they can detect and report suspicious activity rather than unwittingly enabling it.
Sources
This guide is written from primary sources. Each is linked below; claims in the text link to the specific reference they rely on.