You’re halfway through a mortgage application, or finalising a business bank account upgrade, when the lender drops a common request: prove where your money came from. This is when a properly drafted Sample Letter Explaining Source of Funds stops delays and keeps your application moving forward.

Most people freeze at this request. One vague line can get your request denied, even if everything is completely legitimate. This guide breaks down requirements, shares ready examples, and answers every question you might have.

What Makes This Letter Different From Other Financial Documents?

Most people assume this letter just needs to state how much money you have. That is the number one mistake applicants make. Lenders do not just want a number—they want confirmation your money was earned legally, with no undisclosed debts attached.

Getting this letter right can cut application processing time by 70% and avoid automatic flags on your file. Every valid letter will include these core elements:

  • Your full legal name and account/application reference
  • Exact amount and date the funds entered your account
  • Clear, specific origin of the funds
  • List of supporting documents you are attaching
  • Your dated handwritten signature

Different organisations will ask for slightly different levels of detail. Use this quick reference table:

Requesting Party Required Detail Level
Mortgage Lender Full 6 month audit trail for all deposits
Business Bank Transaction origin confirmation
Immigration Office Verified third party proof of income

Sample Letter Explaining Source of Funds For Mortgage Application

Date: 12 October 2024

To: Westwood Mortgage Underwriting Team

Reference: Application ID #782914

Dear Underwriter,

This letter confirms the £42,000 deposit held in my account ending 7621 comes from the sale of my previous property at 12 Oak Street, Manchester. The sale completed on 28 September 2024.

I have attached the signed completion statement, land registry transfer confirmation, and bank transfer receipt. Please contact me on 07911 123456 with any questions.

Yours sincerely,
Sarah Jenkins

Sample Letter Explaining Source of Funds For Business Bank Account

Date: 12 October 2024

To: Barclays Business Onboarding Team

Account Reference: NEWBUS 9174

Dear Onboarding Team,

This letter confirms the £15,000 deposited into my new business account on 10 October 2024 is personal startup capital saved from full time employment over 3 years. No third parties have any claim on these funds.

Attached you will find 12 months of personal bank statements and my most recent P60 employment summary.

Regards,
Mark Thompson

Sample Letter Explaining Source of Funds For Visa Application

Date: 12 October 2024

To: UKVI Immigration Case Working Team

Reference: Visa Application GBR/442981

Dear Case Officer,

This letter confirms the £28,500 shown in my bank statements consists of legal full time wages earned as a software developer, plus an unconditional family gift from my father.

I have attached employment payslips, a gift declaration letter, and my father’s bank transfer confirmation. All funds are freely available for my use.

Yours faithfully,
Priya Patel

Sample Letter Explaining Source of Funds For Gifted Deposit

Date: 12 October 2024

To: Nationwide Building Society Underwriting

Application: Mortgage #661092

Dear Underwriter,

This letter confirms that the £20,000 transferred to my account on 3 October 2024 is an unconditional cash gift from my mother, Linda Carter. This is not a loan, no repayment is required, and she has no legal interest in the property being purchased.

Attached are my mother’s photo ID, bank statement showing the withdrawal, and her signed gift declaration form.

Sincerely,
James Carter

Sample Letter Explaining Source of Funds For Inheritance

Date: 12 October 2024

To: HSBC Anti Fraud Team

Account Number: 001276 89214567

Dear Fraud Team,

This letter explains the £61,000 deposit received into my account on 1 October 2024. This sum is the final distribution from the estate of my late grandfather, Robert Wilson.

I have attached the probate document, estate final statement, and solicitor transfer confirmation. The estate legal team is available for verification if required.

Regards,
Emma Wilson

Sample Letter Explaining Source of Funds For Crypto Withdrawal

Date: 12 October 2024

To: Lloyds Bank Compliance Team

Reference: Transaction Query T91047

Dear Compliance Officer,

This letter confirms the £17,200 deposited to my account on 8 October 2024 is proceeds from the sale of Bitcoin that I purchased incrementally between 2021 and 2023 using my employment wages.

Attached are full trade history logs from the regulated exchange, and matching personal bank statements showing all original purchase transfers.

Yours sincerely,
David Lee

Sample Letter Explaining Source of Funds For Large Cash Deposit

Date: 12 October 2024

To: TSB Customer Support

Account: 102938 77654321

Dear Support Team,

This letter explains the £9,400 cash deposit made at your High Street branch on 7 October 2024. These funds are proceeds from the private sale of my vintage motorcycle, which I have owned since 2018.

Attached are the signed sale receipt, original purchase invoice, and the buyer’s contact number for independent verification.

Regards,
Ian Cooper

Frequently Asked Questions about Sample Letter Explaining Source of Funds

Do I need this letter for every large bank deposit?

No, banks only request this for deposits that trigger anti-money laundering flags. This usually applies to single deposits over 10% of your typical monthly income.

Can I write this letter by hand?

Typed letters are always preferred, but handwritten signed letters are accepted by most organisations. Always include a clear printed name below your signature.

How long should this letter be?

An effective letter is 3-5 short paragraphs maximum. Stick only to facts relevant to the funds. Do not add unnecessary personal background.

Do I need a solicitor to sign this letter?

A solicitor witness is only required for inheritance or large gift amounts over £50,000. For most standard cases your own signature is sufficient.

What happens if I submit an incomplete letter?

Incomplete letters will cause processing delays, or may result in your application being declined entirely. Lenders cannot proceed without clear fund verification.

Can I use the same template for different organisations?

You can use the same base structure, but always adjust the detail level for the requesting party. Always reference your specific application or account number.

How far back do I need to prove the source of money?

Most lenders require a full paper trail for 6 months from the date the funds arrived in your account. Immigration applications may require 12 months of history.

Is a bank statement enough instead of this letter?

Bank statements show money moved, but they do not explain why it moved. This letter connects the transaction to its legal origin for the reviewer.

Every Sample Letter Explaining Source of Funds works best when it is clear, factual, and supported with matching documentation. Avoid vague language, never guess details, and always give reviewers an easy way to contact you with follow up questions. Most application delays from this request happen only because applicants did not understand what was required.

Use the templates shared here as a starting point, and double check that you have attached every supporting document mentioned in your letter. If you are unsure about any detail, ask the requesting team for clarification first before submitting. Taking 15 extra minutes to get this right will save you weeks of waiting later.