CPA Letter Lower The Expense Factor — The Quick Read: Yes, a CPA letter can lower the expense factor, but only on the business bank-statement side of underwriting, not on a straight 1099-income calculation. Lenders start with a fixed default deduction against business deposits, and a signed letter from a qualifying accountant can replace that default with a documented, lower ratio. The 1099-only path calculates income a different way, so the same override doesn’t automatically apply there.
That’s the short version. The rest of this comes down to which document you’re actually working with, who can sign it, and where the mechanic stops mattering entirely — which is sooner than most self-employed borrowers expect.
The Core Rule: Business Deposits Get a Haircut. 1099 Income Doesn’t Work the Same Way.
Lenders treat business bank deposits and 1099 gross payments as two separate calculations. A business account’s gross deposits include money that pays rent, payroll, and supplies before any of it becomes personal income, so underwriters apply a deduction — the expense factor — before counting the rest as qualifying income. A 1099 form, by contrast, reports gross payments to a contractor with no expense information attached at all, so the lender applies its own separate assumption to that number.
Across the wholesale bank-statement programs Lendmire places files through, that business-deposit deduction generally runs on a tiered scale tied to how the business operates, with the exact percentages set by each program’s guidelines based on staffing levels and whether the business sells products or services. A signed accountant letter, or a profit-and-loss method capped at a set share of deposits, can replace that fixed tier with the business’s actual documented ratio. Transfers the borrower moves from their own business into a personal account count in full, with no deduction applied at all.
Under IRS guidance, an independent contractor is considered self-employed and reports income on Schedule C, which already nets out allowable business deductions before it hits the tax return. That Schedule C figure and a lender’s 1099-based qualifying-income number are two different calculations built for two different purposes — the tax return measures taxable profit, and the mortgage file measures repayment capacity.
Key Terms Defined
Expense factor — a percentage a lender subtracts from business bank deposits to estimate what’s left over as personal income, applied before the deposits count toward qualifying.
CPA letter (expense ratio letter) — a signed document from a CPA, enrolled agent, or qualifying tax preparer that certifies a business’s actual operating expense percentage, used to replace the lender’s default assumption.
1099 income program — a qualification method that calculates income from gross amounts reported on 1099 forms rather than from bank deposits, using its own separate expense assumption.
Bank statement loan — a mortgage that qualifies a self-employed borrower using deposit history instead of traditional personal-income documentation, generally over a 12- or 24-month statement window.
DSCR (debt-service coverage ratio) — a ratio that compares a rental property’s income to its full monthly housing payment, used to qualify investment-property loans on the property’s cash flow rather than the borrower’s personal income.
Debt-to-income (DTI) — the share of a borrower’s monthly qualifying income that goes toward debt payments, capped by most lenders on personal-income loan files.
Where a CPA Letter Actually Moves the Number
A CPA letter only matters when the true cost of running the business is lower than the lender’s standing default — it has no function pushing the ratio the other direction. If a consultant runs a low-overhead practice with almost no payroll or inventory, the standard tier for a business with employees may overstate real costs, and a documented lower ratio can meaningfully raise qualifying income. If the default already matches reality, there’s nothing to override.
The letter has to come from someone qualified to certify it — a CPA, enrolled agent, or licensed tax preparer, never the borrower’s own self-declaration. It needs to identify the preparer and the business, state the certified expense ratio, and cover the same period the bank statements do. Underwriters treat this as a routine, expected document, not a red flag. Loan-level exception reports from securitized non-QM pools show reviewers flagging files for exactly this — one exception simply instructed the file to “review uploaded CPA letter explaining the income and expense percentage,” and a separate 2025 filing showed a pool sitting on “pending receipt of the tax preparer letter confirming the expense ratio.” Both examples confirm this document type gets checked, not waved through.
Lendmire’s own coverage of this mechanic goes deeper into what the letter needs to say and who can sign it — see the full breakdown on using a CPA letter to lower the expense factor.
The 1099 Exception: Why the Override Doesn’t Transfer Cleanly
The CPA-letter override belongs to business bank-statement files, and it doesn’t move the same way on a pure 1099-income program. On a 1099-only file, the lender is working off gross 1099 payments rather than deposit history, and any expense assumption applied there is a separate program-level decision — not the same expense-factor mechanic described above. Whether a given lender allows a CPA letter to adjust that separate assumption depends entirely on that lender’s own guidelines.
That distinction matters for anyone weighing which path fits their income. A contractor with several 1099s and a personal account might qualify more cleanly under a 1099 program than under a business bank-statement program with a CPA letter attached — or the reverse could be true, depending on the actual expense structure and which program’s assumption is more favorable. There’s no universal rule that says one path beats the other; it depends on the borrower’s documentation and the specific lender’s guidelines. Lendmire’s comparison of these two documents lays out how the expense factor and CPA letter interact for a 1099 earner in more detail.
What Happens Once the Letter Is Accepted
Once an underwriter accepts the letter, the qualifying-income figure gets recalculated using the certified ratio instead of the default tier, and that new number flows straight into the borrower’s debt-to-income calculation. On most bank-statement files, DTI runs up to 50%, so a lower expense factor that raises qualifying income directly widens how much loan the borrower can support. Reserves still apply on top of that — generally three months of payments up to $500,000 in loan amount, six months up to $1,500,000, and nine months above that, plus two additional months for each other financed property, capped at twelve months.
Co-mingled or pass-through deposits complicate this step regardless of any letter. An underwriter still has to strip out non-recurring transfers or subcontractor pass-through money before applying any expense percentage — certified or default — so a clean CPA letter doesn’t fix messy account activity on its own.
Why a Straight Rental Purchase Usually Skips This Question
The entire expense-factor conversation applies to personal-income qualification — a primary residence, a second home, or a cash-out refinance sized against the borrower’s own cash flow. It generally doesn’t apply to a rental property purchased for investment. That’s because DSCR loans qualify primarily on the property’s rental income covering its payment, subject to lender guidelines, rather than on the borrower’s personal deposits or 1099 receipts.
An investor who also happens to be a 1099 contractor or business owner might genuinely need a CPA letter for their own primary-residence file, and never need one for the rental property they’re financing next door — different program, different qualification logic. DSCR loans are business-purpose, non-owner-occupied products, so they’re reviewed on a different underwriting track than a standard owner-occupied mortgage. On most files in Lendmire’s wholesale network, a rental that clears roughly 1.2x coverage on projected rent gives an underwriter meaningfully more room than one sitting closer to breakeven, and select programs will still review deals below 1.00x coverage with adjusted leverage, subject to lender guidelines — though there’s no fixed number below 1.00 that’s guaranteed to work.
This is worth understanding because the growth in non-QM lending has been driven substantially by investor-purpose business. Non-QM loans made up roughly 5% of all originations in 2024, up from 3% in 2020, and investor and DSCR files grew as a share of non-QM production between August 2022 and August 2025, according to Scotsman Guide’s analysis of non-QM lending trends. The same data shows the average non-QM borrower carried a 776 credit score in 2024 — nearly identical to conventional conforming borrowers — which undercuts the assumption that non-QM files carry weaker credit behind them. Final terms depend on lender guidelines, property type, leverage, and the borrower’s complete credit picture.
What the Bank-Statement Numbers Actually Look Like
Sizing runs from $300,000 up through $30,000,000 across two wholesale tracks — a portfolio non-QM program that carries files to $6,000,000, and a bank-portfolio jumbo program that runs its own ladder on twelve-month statements up to $30,000,000, stepping down to 65% at $5,000,000, 60% at $10,000,000, and 55% at $30,000,000.
Leverage on a primary residence steps down as the loan size climbs, with everything above $4,000,000 reviewed case by case before submission:
| Loan size (primary residence) | Purchase LTV | Cash-out LTV |
|---|---|---|
| $300K–$1M | 90% | 80% |
| $1.5M–$2M | 85% | 75% |
| $2.5M–$3M | 80% | 70% |
| $3.5M–$4M | 75% | 65% |
| $4M–$6M | 65% (case by case) | 60% (case by case) |
Second-home and investment-property leverage generally runs about five points lower than the primary-residence figures at the same loan size, subject to lender guidelines and program eligibility. Above $3,500,000 on a primary residence and $3,000,000 on a second home or investment property, additional overlays kick in — a 700 credit floor, clean housing history, and 48-month seasoning on any past credit event, among others.
Documentation across these programs runs on 12 or 24 consecutive months of bank statements, and business accounts need at least 25% borrower ownership before the deposits even qualify for review. For borrowers whose actual liquid assets tell a stronger story than their deposits do, an asset-based path exists too — qualifying liquid assets divided by 36, 60, or 84 months, depending on DTI and loan size, offers another route entirely apart from the expense-factor conversation.
Lendmire’s consumer mortgage lending for these bank-statement programs runs in 16 states, and every leverage and ratio figure above reflects select wholesale programs, subject to full underwriting — none of it is a commitment to lend.
Common Mistakes That Sink a CPA Letter
Most rejected letters fail for the same handful of reasons. The certified ratio doesn’t match what the tax return shows for the same period, the letter is signed by someone without a real credential or license number attached, or the statement period the letter covers doesn’t line up with the bank statements submitted. Co-mingled personal and business accounts create a related problem — if a personal account is actually funding business operations, underwriters will often still apply business bank-statement rules and the expense-ratio step to it, and a letter that ignores that reality gets flagged. A clean letter states the ratio, matches the period, and comes from someone who’s actually reviewed the business’s real numbers.
This isn’t legal or tax advice. Expense-ratio treatment, 1099 reporting, and Schedule C deductions all involve tax rules that vary by entity structure and individual circumstances, so anyone weighing this decision should talk it through with a qualified CPA or tax attorney before assuming how their own numbers will land.
Frequently Asked Questions
Can I use a CPA letter on a 1099-only program instead of a bank statement program?
Generally not the same way. The CPA-letter override is documented for business bank-statement underwriting, where it replaces a fixed deduction against deposits. A 1099-only program calculates income from gross 1099 payments using its own separate expense assumption, and whether a letter changes that assumption is a lender-specific guideline question rather than a standard industry practice.
Does a CPA letter help if I’m buying a rental property instead of a home?
Usually not, because DSCR loans for rental property qualify on the property’s rental income rather than the borrower’s personal deposits or 1099 receipts. The expense-factor and CPA-letter conversation is largely confined to owner-occupied and other personal-income-based files.
Who is actually allowed to sign a CPA expense-ratio letter?
A licensed CPA, an enrolled agent, or another qualifying tax preparer — never the borrower. The letter needs to identify the preparer’s credentials, name the business, state the certified ratio, and cover the same period the bank statements do.
What if my business has no employees at all — does that change my starting point?
It can affect the default assumptions lenders use. Across Lendmire’s wholesale network, a service business with no employees typically starts from a lower default ratio than a business with staff or physical product, before any CPA letter even enters the conversation.
Does a CPA letter replace the Ability-to-Repay requirement lenders have to follow?
No. The CFPB’s Ability-to-Repay rule requires lenders to reasonably determine a borrower can repay the loan, and that requirement applies to every mortgage, including non-QM bank-statement files. The expense factor and any CPA letter are simply inputs into that broader income analysis, not a substitute for it.
If you’re weighing a business bank-statement file against a 1099-only path — or wondering whether your next purchase should skip personal-income qualification altogether and run on a DSCR loan instead — Lendmire can help you compare the options against your actual documentation, credit profile, and goals.
For current guidelines and terms, see Lendmire’s super jumbo bank statement loan programs page.
About Lendmire
As a DSCR and non-QM mortgage broker, Lendmire — NMLS# 2371349 — connects investors with wholesale lending channels across 40 markets, including Washington, D.C. The property’s rental income, not the borrower’s tax returns, is central to lender review, which works for self-employed operators and portfolios beyond four financed properties.
Lendmire’s Top Mortgage Workplace recognition is documented by Scotsman Guide 2025 Top Mortgage Workplace.
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References
1. IRS – Form 1099-NEC and Independent Contractors FAQ
2. Scotsman Guide – Which groups are driving non-QM lending?
3. Consumer Financial Protection Bureau – Ability-to-Repay Rule
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
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Disclosure information. Lendmire is a state-licensed mortgage brokerage under NMLS# 2371349. Lendmire is not a depository institution, direct lender, or financial advisor — all loans referenced are placed through wholesale lender partners and are subject to each lender's underwriting standards. This article is provided for general informational purposes and is not a commitment to lend, nor does it constitute financial, legal, or tax advice. Loan programs, terms, rates, and qualification standards change without notice and depend on borrower profile, property type, and the state in which the subject property is located. Equal Housing Opportunity provider. NMLS Consumer Access: nmlsconsumeraccess.org.
