What is Source of Wealth?

When you’re applying for a private bank account, buying property or carrying out other high-value financial transactions, you can expect to be subject to a number of compliance checks.

Banks in the UK and worldwide are legally obliged to comply with anti-money laundering (AML) regulations. This often means checking where money has come from and how wealth has been accumulated.

This guide looks at one particular aspect of financial compliance - Source of Wealth (SoW). Read on to find out what it is, why it’s important, what documents are needed to establish SoW and a few examples of when it’s typically used.

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What is meant by Source of Wealth (SoW)?

Source of Wealth (SoW) is a term used to describe the origin of a person, company or entity’s total assets and net worth. This can include property, income generation, savings, business interests and accumulated capital over time. It can factor in everything from professional and business activities to inherited wealth.

Common sources of wealth include:

• Family wealth
• Pensions
• Inheritances
• Divorce settlements
• Investments and dividends
• Sale of assets
• Gifts
• Salary or commission payments.

SoW also has a specific function in the world of financial compliance. In order to comply with anti-money laundering (AML) regulations in place in many countries worldwide, banks and other financial institutions must carry out extensive due diligence checks to determine that the client’s wealth was generated through legitimate means.

According to internal guidance within the UK’s HM Revenue & Customs (HMRC), SoW checks are particularly crucial for customers who are politically exposed persons (PEPs) or if either party in a financial transaction is established in a high-risk third country (HRTC).¹

Financial institutions may also run Source of Wealth checks to ensure that a customer or applicant’s wealth is consistent with their profile.

For example, when a private bank with an ethical stance is onboarding a high-net-worth customer, and wants to check that their wealth isn’t derived from a source that would conflict with the brand’s values.

What’s the difference between Source of Funds (SoF) and Source of Wealth (SoW)?

Another due diligence and compliance check carried out by UK and international banks and financial companies is Source of Funds (SoF).

This is similar to Source of Wealth, but it refers specifically to the origins of the money used in a particular transaction.

For example, if you’re sending a large sum internationally with a money services provider like Wise, it may ask for proof of the source of the funds. This may be a bank statement, investment or savings certificate, solicitor’s letter confirming inheritance or another document showing the movement of the money. However, in this situation, the provider won’t typically ask for full details and documentation proving the source of your entire wealth.

This is needed in order to comply with anti-fraud and anti-money laundering rules both in the UK and internationally.

Examples of Source of Wealth (SoW)

Now, let’s take a look at some examples of when Source of Wealth checks may need to be carried out:

• Opening an account with a private bank or wealth management provider as a high-net-worth individual
• Applying for banking services where a customer’s assets or lifestyle appear significantly higher than their declared income
• Onboarding politically exposed persons (PEPs), their family members or close associates
• Carrying out enhanced due diligence on customers connected to high-risk countries or industries
• Establishing a long-term investment relationship involving substantial existing wealth or assets
• Reviewing customers with complex ownership structures, trusts or multiple international business interests
• Assessing whether a customer’s wealth aligns with a bank’s ethical or reputational risk policies
• Investigating unusually rapid wealth accumulation that cannot easily be explained by a customer profile
• Conducting periodic compliance reviews of existing high-value or high-risk clients
• Verifying wealth generated from business ownership, inheritance, investments or asset sales during customer onboarding.

What documents are needed to establish Source of Wealth?

If you’re ever subject to Source of Wealth checks - such as when opening a private bank account, for example - you’ll need to know what to expect.

Each bank or financial institution is likely to have its own approach, and the exact documents requested will depend on the customer’s circumstances and how their wealth was generated. Ultimately, the documents will need to show how a person accumulated their overall wealth and assets over a period of time.

The following are documents commonly used to establish SoW:

• Employment contracts and historical payslips showing long-term earnings
• Tax returns or HMRC records demonstrating income over multiple years
• Audited business accounts and company ownership records
• Documents relating to the sale of a business, including sale agreements and completion statements
• Investment portfolio statements showing long-term capital growth and dividend income
• Property ownership records and documents relating to property sales
• Probate documents, wills or estate distribution records for inherited wealth
• Pension statements showing accumulated retirement savings
• Trust deeds or trust distribution documentation
• Divorce settlement agreements showing receipt of assets or wealth transfers
• Evidence of long-term savings accumulation across bank or investment accounts
• Shareholding certificates or records of equity ownership in companies
• Accountant or solicitor letters explaining how wealth was accumulated over time.

In some cases, a financial institution may request a combination of documents in order to build a clear picture of how wealth was generated across a person’s career, investments or business activities.

After reading this, you should have a better idea of what Source of Wealth (SoW) is - especially in relation to financial due diligence and anti-money laundering compliance. You’ll also know what kind of documentation to have ready in case you’re ever subject to any SoW checks.

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Sources used:

Sources last checked: 13-May-2026