Source of wealth concerns the broader origin of a person's overall wealth.
The relevant question is: How did this individual or entity acquire their wealth generally?
This may include:
For an entity, source of wealth may require an understanding of the business activities, trading history, ownership, assets and customer base through which its wealth has been generated. For a charity or similar organisation, it may require an understanding of its principal donors, sponsors or funding arrangements.
In many cases, a satisfactory understanding of source of wealth will assist in understanding source of funds.
For example, evidence that a client accumulated substantial wealth through the sale of a long-established business may help explain the source of funds used in a transaction years later.