Lenders Choose Between Twelve And Twenty-Four Bank Statements — The Quick Read: The choice usually comes down to income trend, not preference. A twelve-month window works best when a self-employed borrower’s income is rising, because it isolates the stronger recent period. A twenty-four-month window works best when income is flat or seasonal, because it proves a longer track record instead of letting one strong year carry the file. Many originators run both calculations and use whichever result — and whichever file — clears underwriting.
That’s the short version. The longer version explains how the math actually works, where the exceptions live, and why some investors skip bank statement documentation altogether once they start buying rental property.
Key Terms Defined
Bank statement loan — a non-QM mortgage that qualifies a self-employed borrower using bank deposit history instead of traditional personal-income documentation or a W-2 form.
Non-QM — short for “non-qualified mortgage,” a loan that doesn’t meet the standard agency underwriting box, usually because of alternative income documentation, a higher debt ratio, or an interest-only structure.
Expense factor — the percentage of business deposits a lender assumes goes to overhead before counting the rest as personal qualifying income.
Lookback window — the number of consecutive months of statements a lender reviews to calculate average monthly income; almost always twelve or twenty-four.
DSCR loan — a business-purpose investment loan that qualifies primarily on the rental property’s own income covering its payment, subject to lender guidelines, rather than the borrower’s personal deposit history.
What Actually Decides the Window?
The direction of the borrower’s income, not their preference, drives the twelve-versus-twenty-four decision on most files. A business owner whose revenue jumped in the last year wants a shorter window so the stronger months carry the average. A business owner with flat or lumpy income benefits from a longer window that smooths out any rough patches and shows a lender a longer pattern of consistency.
Scotsman Guide explains how this works across the non-QM industry. A self-employed borrower supplies twelve to twenty-four months of personal or business statements. The lender then calculates qualifying income using either a standard expense factor or a CPA-prepared profit-and-loss statement. Neither time window is inherently “better.” Each one answers a different underwriting question.
Across the wholesale network Lendmire works with, this plays out the same way file after file. Originators frequently run the borrower’s deposits both ways before choosing a path. If the twelve-month average clears the debt-to-income target and the twenty-four-month average doesn’t — or the reverse — that comparison decides which documentation package goes to underwriting.
The Math Behind the Number
Qualifying income isn’t just deposits divided by months — it’s eligible deposits, after stripping out transfers and refunds, divided by the window length, then run through an expense factor if the money came from a business account.
Lenders generally treat personal account deposits closer to net income, without a business haircut, though treatment varies by lender. Business account deposits get discounted because gross revenue isn’t take-home pay. Payroll, rent, and overhead eat into every deposit before any of it becomes personal income.
Across the programs in Lendmire’s network, the expense factor typically lands at one of several tiers, based on business type and employee count. It’s lower for a service business with no employees. It’s moderate for a small business with a handful of employees. It’s higher for a business with more employees or one that sells a physical product. Or an accountant can document the rate directly through a profit-and-loss statement, subject to a program cap. Transfers the borrower moves from their own business account into their personal account count in full — that money doesn’t get discounted twice.
Whichever expense factor applies, it gets combined with the twelve- or twenty-four-month average. Together, they produce one number: average monthly qualifying income. That figure flows straight into the debt-to-income calculation, the same way a traditional employment income figure would on a conventional file.
Twelve Months vs. Twenty-Four Months: Side by Side
| Factor | 12-Month Window | 24-Month Window |
|---|---|---|
| Best fit | Rising income trend | Flat, seasonal, or stable income |
| What it isolates | Recent, stronger period | Longer, averaged history |
| Documentation burden | Fewer statements to gather | Full two years, more paperwork |
| Underwriter read | Wants to see the trend hold | Wants to see consistency over time |
| Risk to the borrower | Older weak months excluded — good | A strong recent year gets diluted |
Neither column wins by default. A borrower with a business that grew fast in the last twelve months and shows nothing unusual before that almost always fares better on the shorter window. A borrower running a seasonal operation — landscaping, tax preparation, event planning — usually needs the longer window because a single twelve-month slice might land entirely inside or outside their busy season.
Personal vs. Business Accounts: Why It Matters
The account type matters as much as the window length, because it decides whether an expense factor applies at all. Personal account deposits generally skip the business haircut. Business account deposits almost always get one, unless a CPA letter documents a lower ratio for that specific business.
Ownership matters too. Business statements typically require the borrower to hold at least a 25% stake in the company generating the deposits — a minority partner’s statements from a business they don’t control usually won’t qualify the same way. And commingled accounts, where money moves in and immediately back out to cover crew payroll or vendor bills, complicate the math regardless of the window chosen. Those pass-through deposits often need a higher effective expense factor, or exclusion from the average entirely, because the raw deposit total overstates what the borrower actually keeps.
Edge Cases That Change the Calculation
A few situations push the twelve-versus-twenty-four decision in a specific direction, and they show up often enough to know in advance.
Declining income. If deposits are trending down, neither window fixes the file the same way a rising trend would. Underwriters read the trend line inside the window, not just the average — a shrinking twelve-month average and a shrinking twenty-four-month average both tell the same story, just at different speeds.
CPA-documented expense ratios. A profit-and-loss letter from a third-party tax preparer can override the standard expense factor entirely, and that override often moves the qualifying income figure more than the window length does.
Seasonal businesses. A contractor, farm-adjacent operation, or event business with genuine seasonal swings almost always needs the twenty-four-month window, because a single year risks landing entirely on one side of the seasonal cycle.
Statement staleness. Statements have to be consecutive and current — a lender reviewing a gap-filled or outdated set will ask for fresh ones regardless of which window the borrower requested.
When the Better Tool Isn’t a Bank Statement at All
For a purchase that’s purely a rental property, the choice between twelve and twenty-four months often doesn’t matter. That’s because the property itself — not the borrower’s personal deposit history — can carry the file. DSCR loans are built for non-owner-occupied investment properties. Since these are business-purpose investor loans, lenders review them differently than a standard owner-occupied mortgage.
Scotsman Guide’s breakdown of non-QM borrower types draws a clear line. Self-employed borrowers use bank statement and 1099 programs that average twelve to twenty-four months of deposits. Real estate investors, on the other hand, increasingly use DSCR loans, which qualify based on the property’s own cash flow instead. An investor buying a fourth or fifth rental doesn’t want to redo a deposit analysis for every new file. A DSCR loan gets reviewed mainly on whether the property’s rental income covers the payment, subject to lender guidelines. This sidesteps the twelve-versus-twenty-four question entirely for that purchase.
Lendmire’s complete DSCR loans guide walks through how that property-income qualification actually works. And for borrowers weighing the two documentation paths directly, this related breakdown of how lenders choose between statement periods covers the mechanics from the other angle.
Sizing and Leverage for High-Income Borrowers
Bank statement financing through Lendmire’s wholesale network runs from $300,000 to $30,000,000 across two overlapping programs — a portfolio non-QM program that carries files to $6,000,000, and a bank portfolio program with its own leverage ladder that carries twelve-month-statement files all the way to $30,000,000: 65% at or below $5,000,000, 60% at or below $10,000,000, and 55% up to $30,000,000, with interest-only capped at 60% or the band’s ceiling, whichever is lower.
Leverage on a primary residence steps down as the loan gets bigger — typically 90% at or below $1,000,000, 85% at or below $2,000,000, 80% at or below $3,000,000, and 75% at the top credit tier at or below $4,000,000, through select wholesale programs and subject to underwriting. Above $4,000,000, every file moves to case-by-case review before it’s even submitted; nothing above that size is a flat “up to” number. Investment property leverage runs roughly five points lower than the primary-residence figures at every size band on most files.
Credit typically needs to clear a 660 floor on the portfolio program, or 700 above the super-jumbo threshold. Debt-to-income can run as high as 50% on strong files, and reserves typically scale from three months on smaller loans to nine months on larger ones, plus two additional months for each other financed property, subject to lender guidelines.
Tax treatment can depend on how the funds are used and how the property is held; investors should keep clear records and speak with a qualified tax professional before relying on any deduction.
Frequently Asked Questions
Can I choose which window I qualify under, or does the lender decide?
In practice it’s often collaborative. Most originators in Lendmire’s network will run a borrower’s income both ways before locking in a documentation package, then use whichever window produces a qualifying figure — and a file — that clears underwriting.
What if my income just jumped in the last year?
A twelve-month window usually helps here, since it isolates the stronger recent period instead of averaging it against an older, weaker year. If the file still needs a longer history to satisfy a specific program’s seasoning requirement, a twenty-four-month package with a supporting CPA letter can sometimes bridge the gap.
Do I need separate statements for personal and business accounts?
Often both, especially if income moves between the two. Personal deposits generally skip the business expense factor; business deposits typically don’t. A lender needs to see both to apply the right treatment to each dollar.
Does a smaller down payment force the twenty-four-month window?
Not directly — the window is driven by income trend, not leverage. But a thinner equity position combined with volatile deposits can push an underwriter toward wanting the longer track record for comfort, even if the math technically clears on twelve months.
Is a bank statement loan the right tool for a rental property purchase?
Sometimes, but often not the best one. A DSCR loan is reviewed on the property’s own rental income rather than the borrower’s personal deposit history, which is why many rental-property investors skip the bank statement path entirely once they’re buying investment real estate rather than a primary home.
If you’re weighing a bank statement path against a DSCR path for an upcoming purchase or refinance, Lendmire can help compare how the numbers work based on the property’s income, the borrower’s credit profile, and the leverage the file actually needs — reach the team at 828-256-2183 or request a quote directly.
For current guidelines and terms, see Lendmire’s super jumbo bank statement loan programs page.
Self-employed borrowers can compare both super jumbo programs on Lendmire’s self-employed mortgages page.
About Lendmire
Lendmire (NMLS# 2371349) is a DSCR-focused mortgage broker that helps arrange investor financing across 40 markets, including Washington, D.C., through wholesale and investor-lending channels. DSCR eligibility is generally reviewed by the lender around the property’s rental income rather than personal income documentation, subject to lender guidelines — which works for self-employed investors, LLC operators, and portfolios above four financed properties. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.
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References
1. Scotsman Guide — Rev Up the Engine for Non-QM Lending
2. Scotsman Guide — Which Groups Are Driving Non-QM Lending?
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
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Required disclosures. Lendmire (NMLS# 2371349) operates as a licensed mortgage broker, not a direct lender or depository. The discussion in this article is general in nature and should not be relied upon as financial, legal, or tax advice — every investment scenario is unique and should be reviewed by a qualified professional. Any loan inquiry is subject to lender underwriting, and this article is not a commitment to lend or a guarantee of approval. Mortgage rates, loan terms, and program guidelines vary by borrower, property, and state, and may change without notice. Equal Housing Opportunity. Verify licensure at NMLS Consumer Access.
