Source of funds vs source of wealth (SoF vs SoW)
Source of funds (SoF) is narrow and transaction-specific: where did this particular money used to deposit or stake come from (e.g. this month's salary, sale of an asset, a specific bank account). Source of wealth (SoW) is broad: how did the person accumulate their total wealth and net worth over time (e.g. a career, a business sale, inheritance, investments). Establishing SoF answers 'where did this money come from?'; establishing SoW answers 'why does this person have the assets they do at all?'. High-risk cases usually need both, with SoW providing the wider context that supports or undermines the SoF explanation.
SoF = origin of the specific funds in play now (the deposit, stake or transaction); SoW = origin of the customer's entire net worth.
SoF is verified with evidence tied to the money itself (payslips, bank statements, sale-of-asset documents); SoW is verified with evidence of overall wealth accumulation (employment history, company accounts, inheritance/probate, investment records).
Establishing SoW is a standard requirement of enhanced due diligence and is mandatory for PEPs; SoF checks are triggered more broadly by high spend, unusual activity, or risk flags.
A plausible SoF can still be suspicious if it is inconsistent with the customer's known SoW (e.g. large deposits that dwarf a modest declared income).
Both are AML/CFT tools, but they answer different questions and are commonly tested together to detect layering of criminal proceeds.
Declared information should be corroborated with independent evidence, not simply accepted at face value.
Gambling operators typically trigger SoF checks when a player's deposits or losses rise beyond thresholds set in their risk assessment, or when spend looks inconsistent with what is known about the customer, and the UK Gambling Commission expects these checks (alongside affordability considerations) rather than allowing unchecked high spend. For VIP/high-roller players and any PEP, operators are expected to go further and establish source of wealth, so that the overall picture, not just the immediate deposit, is understood.
Reference, not advice. This is a teaching summary of the AML framework — not legal advice, and not an operational compliance procedure. Confirm requirements against the primary regulator and your own counsel.