Definition
Source of funds (SOF) is the origin of the specific money a player is using to gamble - the salary payment, the sale proceeds, the transfer that funded this deposit. Source of wealth (SOW) is the broader origin of a person's overall assets - how they came to have money at all: employment, business ownership, inheritance, investments.
Anti-money-laundering rules require licensed gambling operators to establish both, to a depth proportionate to the risk the player presents, and to keep evidence.
The purpose is to make sure the money being staked is legitimately obtained and that gambling activity is consistent with the player's known circumstances. It is also a responsible-gambling control: if a player is depositing far more than their income could support, that is a marker of possible harm as well as possible financial crime.
In context
Operators apply SOF/SOW checks on a risk-based trigger model rather than to everyone equally: cumulative deposits or losses crossing set thresholds, rapid escalation of stakes, a politically exposed person or a sanctions or adverse-media hit, use of higher-risk payment methods, or behaviour inconsistent with the player's stated profile. Evidence ranges from payslips and bank statements for straightforward cases to company accounts, tax filings, sale contracts or professional confirmations for larger or more complex wealth.
Until satisfactory evidence is provided, the operator may cap or freeze deposits and withhold withdrawals.
For affiliates, SOF/SOW is mostly relevant as context for two things they do see. First, it is a major reason for withdrawal delays and account restrictions that generate player complaints - understanding that the operator is legally required to ask helps set accurate expectations in content.
Second, regulators increasingly criticise operators for chasing high-deposit players without checking affordability, and affiliate marketing that targets or celebrates heavy spending sits uncomfortably against that. Several large regulatory penalties in gambling have centred on operators taking substantial sums from players without establishing source of funds and without acting on the affordability signals those deposits represented.
Worked example
A player's deposits reach a threshold within three weeks. The operator requests source-of-funds evidence and pauses further deposits until it arrives.
The player provides payslips that do not support the amounts; the operator restricts the account and files an internal review. An affiliate whose content had promoted "high-roller" bonuses to this segment is asked by the operator to change the messaging.
Related terms
Frequently asked questions
Browse more iGaming terms in our glossary.
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