Large Bank Deposit Flagged by Your Mortgage Lender: What to Do

I’m Michael DiVita — DRE #01372066 | NMLS #241655, DiVita Home Finance (DRE #01818285 | NMLS #323700), Tiburon, CA. I’ve been in California mortgage lending since 2000 and founded DiVita Home Finance in 2007. I’m known as a creative mortgage broker: when a bank says no, I find the lender and the loan structure that can say yes. Call (800) 239-1103.

You’re weeks away from closing on your California home when your loan officer calls: “We need you to explain this large deposit in your bank account.” It’s one of the most common — and most stressful — surprises in the mortgage process. Almost always it’s fixable. Here’s why lenders flag deposits, exactly what counts as “large,” what documentation clears it, and what to do if a deposit simply can’t be sourced.

Why Lenders Care About Large Deposits

Lenders have to verify that your down payment, closing costs, and reserves are legitimately yours and weren’t borrowed. An undisclosed loan that shows up as a deposit would secretly add debt — changing your debt-to-income ratio and risk profile without the lender knowing. So underwriters read your recent bank statements (typically the most recent two months for conventional loans) line by line and ask about anything that isn’t clearly payroll or a transfer between your own verified accounts.

What Counts as a “Large” Deposit?

For both Fannie Mae conventional loans and FHA loans, a large deposit is a single deposit that exceeds 50% of the total monthly qualifying income on the loan — meaning the combined income of all borrowers. On a household income of $150,000 a year ($12,500 a month), any single non-payroll deposit over $6,250 needs to be documented.

A few important nuances:

• Transfers between your own verified accounts don’t need further explanation when the source is clear on the statement and you’ve provided statements for both accounts.
• Refinances: Fannie Mae doesn’t require you to source large deposits on a refinance, though the lender still has to account for any borrowed money.
• Partly documented deposits: only the unsourced portion is measured against the 50% threshold.
• Individual lenders can be stricter — some ask about any deposit that looks unusual, regardless of size.

What Lenders Will Ask For

When a deposit is flagged, you’ll be asked for a short Letter of Explanation (LOE) plus a paper trail. What clears it depends on the source:

The Problem With Cash Deposits

Cash is the hardest thing to source because there’s no paper trail. Conventional lenders generally won’t count undocumented “mattress money” toward your down payment. FHA does allow cash saved at home in limited cases, but you’ll need to deposit it and explain in writing how and over what period you accumulated it, and the lender has to find that reasonable given your income and banking history. Two warnings:

• Don’t split up cash deposits to stay under $10,000. Breaking deposits into smaller amounts to avoid bank reporting is called structuring, and it’s a federal crime even when the money itself is perfectly legal.
• If you earn cash in your business (restaurants, salons, contractors, tips), tell me at the start. A self-employed borrower whose cash receipts are deposited regularly into a business account is often a better fit for a bank statement loan, which is built around deposits in the first place.

Gift Funds: Documenting Them Correctly

Gifts from family are allowed on most loan programs, but they need specific paperwork. The donor signs a gift letter stating the dollar amount, the donor’s name, contact information and relationship to you, and that no repayment is expected (many lenders also want the property address). Then the lender needs to see the money move — a copy of the donor’s check and your deposit, a wire confirmation, or the donor’s funds wired directly to escrow. Who can give, how much, and when you must contribute your own money varies by loan type; see my full guide to gift funds for a California down payment.

What If a Deposit Can’t Be Sourced?

This is where a lot of borrowers panic unnecessarily. Under Fannie Mae guidelines, an unsourced large deposit doesn’t automatically kill the loan — the lender subtracts it from your verified assets. If what’s left still covers your down payment, closing costs, and required reserves, the loan can move forward. That’s why I ask about big deposits at pre-approval, not at underwriting: sometimes we simply don’t need that money, and sometimes a different account or a longer-seasoned balance solves the problem.

When the numbers don’t work without the deposit, the options include documenting it as a gift after the fact (if it truly was one, with a proper gift letter and the donor’s bank statement), using funds that have been in your accounts longer, or restructuring the loan. As a broker with access to 40+ wholesale lenders, I can also match you to a lender whose asset guidelines fit your situation — which is often the difference between a denial and a closing.

How to Prevent Deposit Issues

• Talk to your loan officer before moving money. Tell me about gifts, asset sales, and transfers you’re planning so we can document them as they happen.
• Consolidate funds early. Money that has sat in your account for a couple of statement cycles is considered “seasoned” and generally isn’t questioned the same way. (This is about avoiding paperwork headaches — never about hiding a loan. Borrowed money must be disclosed.)
• Keep the paper trail. Selling a car, stock, or crypto? Save the sale documents and transfer records before you deposit the proceeds.
• Use checks, wires, or electronic transfers instead of cash for any significant amount.
• Don’t open new credit or take cash advances to build your down payment.
• Provide full statements — every page, including the blank ones. Missing pages trigger conditions of their own.

Will It Delay My Closing?

A flagged deposit doesn’t automatically delay closing — slow or incomplete answers do. When your lender asks, send the explanation letter and supporting documents right away, ideally within 24 hours. Complete, organized documentation lets underwriting clear the condition quickly and keeps your closing timeline on track.

Frequently Asked Questions

What counts as a large deposit for mortgage purposes?

For Fannie Mae conventional and FHA loans, a large deposit is any single deposit that exceeds 50% of the total monthly qualifying income on the loan. On a combined $150,000 annual income, that is any non-payroll deposit over $6,250. Transfers between your own verified accounts don’t need further explanation, and some lenders ask about smaller unusual deposits too.

Do I have to explain large deposits on a refinance?

Under Fannie Mae guidelines, documentation or explanation of large deposits is not required on a refinance, although the lender still has to account for any borrowed funds. Individual lenders may still ask.

What happens if I can’t document where a deposit came from?

On a Fannie Mae loan, the lender subtracts the unsourced amount from your verified assets. If the remaining funds still cover your down payment, closing costs and reserves, the loan can proceed. If not, you’ll need another documented source of funds or a different loan structure.

Can I use cash I saved at home for a down payment?

Conventional lenders generally won’t count undocumented cash. FHA allows cash on hand in limited cases if you deposit it and explain in writing how you accumulated it, and the lender finds that reasonable based on your income and banking history. Never split cash deposits to stay under $10,000 — that is illegal structuring.

How do I document gift funds for a mortgage down payment?

The donor signs a gift letter stating the amount, their name, contact information and relationship to you, and that no repayment is expected. You also need proof of the transfer, such as the donor’s check and your deposit receipt, a wire confirmation, or funds wired directly to escrow.

Will a flagged bank deposit delay my mortgage closing?

Not by itself. Delays happen when the explanation and documents arrive slowly or incomplete. Respond within a day with a clear letter of explanation and the paper trail, and the condition usually clears quickly.

Related Resources

• Gift Funds for a Down Payment in California
• Mortgage Preapproval Checklist
• How Much Down Payment Do You Need in California?
• California Closing Costs
• Bank Statement Loans
• RSU & Equity Compensation Mortgages
• Mortgage Application Denied? What to Do Next