Money laundering is the engine that keeps the criminal world running. Just as legitimate businesses need the financial system to keep moving—banks, insurance, and regulations—criminals rely on money laundering to make their dirty money look clean and keep their operations alive. Without it, everything falls apart.

The property market has always been a favourite playground for money launderers, and it remains a popular choice. According to Europol, 41% of criminal networks use property deals to launder their illegal profits. Real estate offers a tried-and-tested method, often cloaked with an air of legitimacy that makes it much harder to detect and prevent. This helps criminals continue their activities and evade the authorities, causing significant harm to society.

But it’s not just about shady deals and dodgy transactions. To understand why money laundering is such a big problem, you need to think about where that money comes from. Europol’s research shows that 82% of Europe’s biggest criminal networks focus on core crimes like drug trafficking or organised property crime. The other 18% operate as “poly-crime networks,” getting involved in anything from human trafficking and fraud to smuggling. What’s even more concerning is that 68% of these gangs use violence as part of their operations. This isn’t just white-collar crime—it’s a world where violence and coercion are the norm.

These aren’t small-time crooks; they’re hardened criminals who have made a career out of their illegal activities. Many of these criminal networks have been active for over a decade, proving their resilience and adaptability. This is a tough, relentless world they operate in, and it takes all of us in the property industry to stay alert and push back.

Criminals are quick to adapt, but there are still tell-tale signs of money laundering if you know what to look for. Clients who are secretive or evasive, sudden changes in legal advisers, and transactions that seem outside the norm are all red flags. A client with no local ties or a lack of a good reason for choosing your firm could also be suspicious. Unexplained urgency or last-minute changes to the deal might indicate something shady. Watch out for people who seem to know too much about money laundering processes, transactions that are unusually large or frequent, clients who don’t seem to care about the details, and strange sources of money or unexplained funds. Odd links between people, activities, or different countries can also be signs that something isn’t right.

If you notice anything that feels off, dig deeper. Do your own research or ask the client more questions. How they respond can help you determine if there’s a real issue or just a misunderstanding. Keep notes on everything—every question, every answer, and every bit of research. If questions come up later, whether from your boss or law enforcement, those records could be crucial.

To stay ahead and protect yourself and your firm, you need to be vigilant. Always be on the lookout for red flags, stay curious, and keep thorough records. Make sure to follow your firm’s reporting rules, too. Property professionals are on the front lines of the fight against money laundering. By staying alert and taking action, you can help keep dirty money out of the system and make society safer for everyone.

Harriet Holmes is a compliance and anti-money laundering specialist at Thirdfort.