A bank statement showing enough money in the account answers one question: can this buyer pay? It says nothing about where the money came from, and nothing about how the buyer built the wealth behind it. Those are separate checks with separate answers, and running them together is the most common way a property file falls apart under inspection.
What follows sets out what each check asks, which documents usually answer it, and where the UK, the US and FATF stood as of 18 September 2026. It is general information for people working in or buying through the property sector, not legal advice, and the rules differ by country and by the supervisor you answer to.
Proof of funds, source of funds and source of wealth
Three terms, three different questions. Agents and buyers use them interchangeably, and supervisors do not.
| Concept | What it means | Typical evidence | The question it answers |
|---|---|---|---|
| Proof of funds (POF) | Evidence that the money for the purchase is available now | Bank or investment statement, a solicitor’s letter confirming funds held, a mortgage offer | Is the money there? |
| Source of funds (SOF) | Where the money being used in this particular transaction came from | Sale contract for a previous property, payslips and employment contract, inheritance or probate papers, loan agreement, company accounts and dividend records | Where did this money come from? |
| Source of wealth (SOW) | How the person accumulated their overall wealth, not just this pot of money | Business ownership records, a documented income history, investment portfolio history, inheritance documents | How was this person’s wealth built? |
The gap between the second and the third is where files usually fail. A buyer can show that £400,000 arrived from the sale of a flat, and that is a clean source of funds. It still leaves open how they came to own the flat, which is a source-of-wealth question. Whether you need to ask it depends on the risk, and in some cases the law decides for you.
Why property attracts this level of checking
Property moves a lot of value in a single transaction, the asset holds its value, and ownership can sit behind a company or a trust that takes work to unpick. A purchase without a mortgage also removes a bank from the chain, and with it the customer due diligence that bank would have run. That is why cash buyers get named specifically in supervisory guidance rather than treated as ordinary.
FATF reviewed the sector in 2022 and found that estate agents often understand these risks poorly and fail to mitigate them. That assessment, not any single scandal, is what sits behind the tightening of the last few years.
Documents that usually satisfy a source-of-funds check
What counts as adequate evidence depends on the source. The pairings below are common practice rather than a legal list, and your supervisor may expect more.
| Where the money came from | What usually evidences it |
|---|---|
| Employment income | Payslips covering a meaningful period, employment contract, bank statements showing the salary arriving |
| Sale of a previous property | Completion statement, the sale contract, the solicitor’s client-account transfer |
| Business income or dividends | Filed company accounts, dividend vouchers, corporation tax records, the company’s bank statements |
| Inheritance | Grant of probate or its local equivalent, the will, a letter from the estate’s solicitor or executor |
| Gift | A signed gift letter stating the money is not a loan, plus the giver’s own source of funds evidence |
| Loan or mortgage | The facility agreement or mortgage offer, and evidence of the lender’s identity |
| Sale of investments or shares | Contract notes, broker statements showing the disposal and the proceeds |
| Divorce or court settlement | The court order or consent order, and the transfer that followed it |
| Cryptoassets | Exchange records tracing the fiat purchase, the disposal, and the transfer into a named bank account |
One point worth making plainly, because the opposite is often claimed: a blockchain record does not establish that funds are legitimate. It shows that a transfer happened between addresses. Tying an address to a real person, and that person’s money to a lawful origin, still takes the ordinary documentary trail.
If you are the buyer
Agents ask late and then need answers fast. Assembling this before you offer saves weeks.
- Work out which pots of money are funding the purchase, and treat each one as its own question.
- Pull statements that show the money arriving, not just the balance on the day you were asked.
- For a gifted deposit, get a signed letter from the giver confirming it is a gift rather than a loan, and expect the giver to be asked where their money came from.
- Keep the paperwork from whatever generated the money: the completion statement, the probate grant, the contract note.
- Expect to explain anything that looks out of proportion to your income, because that is the specific thing agents are told to check.
- Do not move money between accounts to consolidate it before you are asked. It breaks the trail and creates work for everyone.
What the agent or compliance team actually does
The shape of the review is fairly consistent, whatever the jurisdiction calls it.
- Identify the customer and, where the buyer is a company or trust, the beneficial owners behind it.
- Assess risk before deciding how deep to go. Cash purchase, an offshore structure, a politically exposed person, or a high-risk country all push the file towards enhanced checks.
- Establish source of funds for the transaction, and source of wealth where the risk or the law requires it.
- Test proportionality: does the money make sense against what is known about the buyer?
- Record the reasoning, not just the documents. If a supervisor asks why you accepted what you accepted, the file has to answer.
- Monitor for change, because a property transaction runs over weeks or months and the funding can shift inside that window.
Red flags
Most of these come straight from supervisory guidance rather than from anything exotic.
- The source of funds changes partway through the transaction.
- A last-minute switch of mortgage provider, or a mortgage that disappears and becomes a cash purchase.
- A deposit gifted by someone with no obvious connection to the buyer, or a giver who will not evidence their own funds.
- Funds that are out of proportion to the buyer’s known income.
- Payment from a third party who is not a party to the transaction.
- A price that sits well above or below market value without an explanation.
- Ownership through layered companies or trusts in jurisdictions that make beneficial ownership hard to see.
- Reluctance to provide ordinary documents, or documents that arrive altered.
The sources that cause the most trouble
Gifts, inheritance and business income account for most of the difficult files. A gift needs the giver’s source of funds as well as the buyer’s, which doubles the work and often surprises families. Inheritance is simple enough with a probate grant. Without one it rarely is, especially where the estate sits abroad. Business income means reading the accounts well enough to judge whether the drawings are plausible against what the company actually earns.
Third-party payments are the ones to be most careful with. Money arriving from someone outside the transaction is not automatically suspicious, but it needs an explanation that holds, and the third party becomes someone you have to know something about.
United Kingdom
Estate agency businesses are supervised by HMRC under the Money Laundering Regulations 2017. HMRC’s sector guidance, AMLG2200, is specific about source of funds and wealth, and the points below come from it.
- Because a sale or purchase runs over time, HMRC treats it as a business relationship. That brings ongoing monitoring, and it may require verifying both source of funds and source of wealth.
- Verifying source of funds and source of wealth is required when you carry out enhanced due diligence.
- Where the customer is a politically exposed person, or from a country subject to a FATF call for action, verifying both is mandatory as part of those enhanced measures.
- HMRC tells agents to take extra care with cash buyers, precisely because no mortgage lender has checked anything.
- Gifted deposits and a late change of mortgage provider are called out as things to look at.
- The test HMRC sets is proportionality: does the money funding the purchase or the deposit match what you know about the customer’s income?
- Document the reasoning. HMRC’s own wording asks whether you could explain and evidence the decision you made and why you made it.
On reporting, the guidance is narrower than it is often paraphrased. Where customer due diligence cannot be completed, an agent must not proceed with the transaction, must end the business relationship, and must consider whether a Suspicious Activity Report is required. A mismatch between funds and expectations triggers that consideration. It is not an automatic filing obligation, and describing it as one misstates the law.
United States
The US position is unsettled, and anything written about it needs a date attached.
FinCEN’s Residential Real Estate Rule would have required reporting persons to file Real Estate Reports on certain non-financed residential transfers. On 19 March 2026 the US District Court for the Eastern District of Texas ruled that FinCEN lacked the authority to issue the rule and ordered it vacated. FinCEN, through the Department of Justice, has appealed.
- While that order stands, reporting persons are not required to file Real Estate Reports and face no liability for not filing.
- If the order is overturned, FinCEN has said reporting will not have to be filed retrospectively for transfers that fell in the gap.
- Two other courts rejected challenges to the same rule, so the question is contested rather than settled.
- FinCEN issued its explanatory FAQs on this on 18 May 2026 and has said it expects to publish further guidance.
A note on a figure that circulates widely. Older material on US property rules cites a $300,000 threshold drawn from FinCEN’s Geographic Targeting Orders. That number never applied across the country: the orders covered named counties and were directed at title insurance companies. Anyone relying on a threshold quoted second-hand should read FinCEN’s current pages instead.
Separately, and unaffected by the above, the Bank Secrecy Act continues to require financial institutions to report suspicious activity. A mortgage lender remains inside that regime whatever happens to the real-estate reporting rule.
FATF and the risk-based approach
FATF does not make national law. It sets standards that member countries implement, and its sector guidance explains how a risk-based approach is meant to work in practice — assess the risk first, then match the depth of the checks to it, rather than applying the same procedure to every buyer.
The relevant document is the Risk-Based Approach Guidance for the Real Estate Sector, published on 26 July 2022. FATF flags on its own page that this guidance predates later revisions to the standards, including the 2025 changes to Recommendation 1. Treat it as the framework, and your national rules as the obligation.
Handling the documents
Source-of-funds files hold payslips, bank statements, probate papers and identity documents — material that causes real harm if it leaks, and that data protection law treats accordingly. Collect what the risk justifies rather than everything available, store it where access is controlled and logged, keep it for the period your regulator requires and no longer, and tell the customer what you are holding and why.
When to get specific advice
Take proper advice when the buyer is a politically exposed person or connected to one, when funds cross several jurisdictions, when the structure involves trusts or companies you cannot see through, when a source cannot be evidenced at all, or when you are weighing whether to file a report. Those decisions carry legal consequences and depend on facts this page does not have.
Sources and verification
Every regulatory statement above was checked against the primary source on 18 September 2026. Where a position is contested or in flux, the page says so rather than picking a side.
| What it supports | Source |
|---|---|
| UK obligations for estate agency businesses, including source of funds and wealth, cash buyers, gifted deposits and record-keeping | HMRC, AMLG2200 — Estate Agent Business Guidance |
| Status of the Residential Real Estate Rule, the March 2026 vacatur, the appeal, and the absence of a filing requirement | FinCEN, Residential Real Estate FAQs and Residential Real Estate Rule |
| The risk-based approach for the sector, and FATF’s finding on how well the sector understands its risks | FATF, Risk-Based Approach Guidance for the Real Estate Sector, 26 July 2022 |
Disclaimer. This page is general information, not legal advice, and it has not been reviewed by a qualified lawyer. AML obligations depend on your jurisdiction, your supervisor and the facts of the transaction. Take professional advice before acting on anything here.
