Understanding Source of Wealth vs. Source of Funds for UK AML Compliance

28th July 2026

The two terms, Source of Wealth and Source of Funds, can regularly be confused with each other, but understanding the distinction can be a crucial part of ensuring your remain AML Compliant, particularly in high net-worth client and business relationships. As per HMRC Guideline, these checks are a requirement when your client is a PEP, family member or close associate of a PEP, or if a business relationship is with a person established in a FATF Call for Action country, or a relevant transaction where either party is established in such a country. If a client is determined to be a high risk by your business risk assessment, this would also trigger a Source of Funds or Source of Wealth check, depending on the business relationship or transaction.

Source of Wealth (SoW)

Source of wealth, or SoW checks, seek to determine the overall accumulation of wealth. It goes beyond the money involved in a single transaction and instead looks at the customer’s broader financial background and long‑term income streams. This is to confirm the funds are legitimate, plausible and verifiable in order to remain AML compliant.

Concerns may arise if the sources of wealth do not match the net worth of your client, their risk profile and the business relationships.

Examples of Source of Wealth

• Long‑term employment income
• Business ownership or entrepreneurial activity
• Property investments
• Inheritance
• Sale of a company 
• Pension savings
• Long‑term investment growth

Source of Funds (SoF)

Determining the source of funds, or performing a SoF a check, seeks to understand the origins of money used in a particular transaction. The question to be answered is how and where the client got the money for the specific transaction.

Examples of Source of Funds

• Salary and Bonuses
• Proceeds from a recent property sale
• A specific dividend payment
• A loan drawdown
• A transfer from an investment account
• A gift used to fund a purchase

Why this isn’t as simple as checking bank statements

SoF and SoW checks require much more than checking bank statements. To identify funds and wealth, the origins of the money need to be identified. Clients should be able to provide a trail from the source of funds to their bank account.

Bank statements alone cannot answer key questions: how the money was earned, why the funds were transferred and whether this aligns with the customer profile. Statements provide limited information on incoming payments, making it easy to disguise payments from third parties, offshore companies and give no context for cash deposits.

To thoroughly understand a client’s wealth, often years of proof is needed, through documentation such as payslips, investment account information and inheritance letters.

The Key Difference

A SoF check is seeking to identify the funds for a single transaction, whilst SoW checks seeks to understand the sources of wealth of a customer as a whole. See more information on putting these checks into practice as a supervised business on the HMRC website.

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