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The distinction is standard anti-money-laundering practice, not a casino invention. Source of funds means the origin of the specific money used in a transaction — this deposit, that transfer. Source of wealth means how the customer accumulated their wealth overall — the story of the balance, not the journey of one payment.
For gambling operators in the UK, due diligence on both is expected where risk requires it, with documented proof of income or wealth for high-spending customers, and particular scrutiny where funds are obscure or higher-risk — recycled winnings and cryptoassets are both named in that category. Crypto deposits may only be accepted where the operator can satisfy both its AML duties and its safer-gambling duties, including identifying source of funds and source of wealth.
What each request is actually asking for
| Request | Question being asked | Evidence that answers it |
|---|---|---|
| Source of funds | Where did this specific money come from? | Bank statement showing the credit and the transfer out; payslip for the salary that funded it; sale documentation; a transaction trail for crypto |
| Source of wealth | How did you come to have money at all? | Employment contract or several years of payslips; tax returns; company accounts or dividend records; documentation for a property sale, inheritance or settlement |
Sending a single month's statement in answer to a source-of-wealth request is the commonest cause of a verification loop. The statement shows a balance existing; the question was how it came to exist.
Why the request arrives when it does
Three separate triggers get blamed on each other:
- AML risk. Deposit size, deposit pattern, payment method, jurisdiction, or a change in behaviour. No published threshold exists, which is why the timing feels arbitrary.
- Customer-interaction duties. A separate obligation about harm, not crime, that can produce a very similar-looking email.
- Affordability schemes. Threshold-based, and frequently confused with the other two — see UK affordability checks, where the light-touch check uses public records rather than documents at all.
An operator is entitled to ask before paying out, and a request at withdrawal time is legitimate even when it feels punitive. What is not acceptable is a request with no stated basis and no stated scope.
How to get through it in one round
- Ask which of the two is being requested and for what period. One email saves a week.
- Match the document to the question using the table above. Continuity matters: a statement that shows the salary arriving and the deposit leaving answers a funds question in one file.
- Send complete documents. Full pages, unedited, names and dates visible. Cropped screenshots are the second commonest cause of a loop.
- Use one payment method in your own name. Third-party payments are refused almost everywhere and will not be unwound by explanation.
- Keep a trail for crypto and for recycled winnings. Both are explicitly treated as higher risk, so both need more evidence, not less.
- Verify at sign-up, not at withdrawal. The single change that removes most payout delays.
If it stalls anyway
Put one written request to the operator naming the documents supplied, the date supplied, and the specific question you understand to be outstanding. If that goes unanswered, escalate to the ADR provider the licence requires the operator to name — not to support, and not to a public post. Where a win is being withheld rather than a verification completed, the terms being relied on matter too: see "malfunction voids all pays".
Two things are worth knowing about what happens to the account while the check runs. The balance is normally frozen rather than confiscated, and the freeze applies to the withdrawal rather than to the deposit history: an operator that has asked for documents is required to hold the funds until it is satisfied, which is why the delay is not something support can waive as a gesture. And a check that has been opened does not close itself. It ends when a named person accepts a named document, so every message you send is worth addressing to the question rather than to the inconvenience — dates, amounts, the document supplied, nothing else. A chargeback at this point is the one move that makes the outcome worse: it is treated as a breach of the terms rather than as pressure, and it usually closes the account with the balance still inside it.
More on account and payment mechanics is in Money & Accounts and Payments. Our own rating method, including what an undocumented payout route does to a score, is in how we rate.
Sources
- ComplyAdvantage — definitions: source of funds as the origin of specific funds, source of wealth as accumulated wealth overall
- Gambling Commission AML requirements, summarised — documented proof of income or wealth for high-spending customers; cryptoassets treated as high risk
- Howard Kennedy — operator failings: absent guidelines on when SOF/SOW checks apply, insufficient scrutiny of recycled winnings and crypto
- Norton Rose Fulbright — money laundering controls in the gambling sector
Nothing here is legal or financial advice. Read against the sources above on 27 September 2026; an operator's own published policy takes precedence for that operator.