The Quick Read: Pick the window that gives you the highest qualifying income you can fully document: twelve months when your recent deposits run above the older ones, twenty-four months when income is flat, seasonal or uneven, and ask your broker to run both averages on the same statements before you submit, because programs differ on which windows they offer. A standard DSCR loan skips this decision entirely. The 12-versus-24 choice only exists on bank-statement programs, which qualify you on deposits instead of traditional personal-income documentation.
- A rising income usually favors 12 months, because it isolates your strongest stretch.
- A flat, seasonal or uneven income usually favors 24 months, because it smooths the swings.
- A falling income can look better on 24 months, but underwriters read the trend and may weigh the recent months more.
- Some programs offer only one window, so availability can decide for you.
- The best window is the one that is both eligible and fully documented. Run both and compare.
Does a DSCR Loan Even Use 12 or 24 Months?
No. Many investors assume every investor loan needs a year or two of statements, and that is a mix-up between two different products. A DSCR loan is reviewed primarily on property-level rental income covering the payment, subject to lender guidelines. It asks for recent statements to show reserves and the source of your down payment. It does not calculate your personal income and it does not run a debt-to-income test.
A bank-statement loan works the other way around. It qualifies you, the borrower, on the cash moving through your accounts. That fits founders, physicians, attorneys, consultants, contractors and investors whose traditional personal-income documentation shows far less than they actually earn, because write-offs and depreciation shrink the taxable number.
So the first question is which product your file needs. If you own several rentals and your personal income paperwork is thin, DSCR may remove the whole question. Lendmire’s complete DSCR loans guide covers how that path works. If you are buying a primary residence, a second home, or a high-balance property and your own income has to carry the file, read on.
What Do 12 and 24 Months Actually Mean?
The window is the number of consecutive monthly statements the program reads to calculate your income. Twelve months means the most recent twelve in a row. Twenty-four means the most recent two years in a row.
Three details matter more than people expect:
- Consecutive means no gaps. Every page of every statement for every account you rely on has to be there. A missing month or a skipped page becomes a condition.
- Account type is your choice, within program rules. Trade press such as Scotsman Guide notes that a typical file uses 12 to 24 months of personal statements, business statements, or a combination. It also notes that lenders want consistent monthly deposits and that programs are not one size fits all.
- Transaction histories do not substitute. Across the programs in Lendmire’s wholesale network, a printed activity list is not a statement.
The window is also set by the program, not by a universal rule. Some programs take either 12 or 24 months. Others take only 12. That is why the first step in any file is matching the borrower to a program that offers the window that fits.
How Does Underwriting Turn Statements Into Income?
Underwriters follow a fixed sequence. Knowing it lets you predict the result before anyone runs it.
1. Pick the account type. Personal statements suit borrowers who are paid directly. Business statements suit owners whose revenue runs through an entity. Ask before you submit whether a program allows a combination.
2. Pull the window. Gather all pages of 12 or 24 consecutive months for each account in use.
3. Screen the deposits. Underwriters remove loan proceeds, refunds, owner injections, one-time items and shuffling between accounts that are not the business’s own revenue. What remains has to look like your business.
4. Average. Eligible deposits are added up and divided by the number of months in the window.
5. Apply ownership and expenses. Income is prorated to your ownership share. Business statements generally need at least 25% ownership. An expense ratio then trims the deposits, because revenue is not profit.
6. Qualify. The resulting monthly income feeds the debt-to-income test, alongside credit, reserves and the property.
Step 5 is where programs differ most. Through select wholesale programs, subject to full underwriting, the common business-statement ratios are 20% for a service business with no employees, 40% for one to five employees, and 50% for six or more employees or any product business. An accountant-prepared ratio can replace the fixed one. A profit-and-loss method is another route, capped at 80%.
You may see 50% quoted online as the rule. It is a common example, not a rule, and programs treat personal accounts differently. One advantage worth knowing: a transfer from your own business into your personal account counts at 100% on the programs in Lendmire’s network, because it is the business’s revenue reaching you. Transfers that merely move your own money between accounts are not income and get removed. That is why many owners qualify on personal statements even when the business runs the money.
How Do the Two Windows Compare?
Both windows use the same math. Only the number of months in the average changes. The table shows where each one helps and where it hurts.
| Factor | 12 Months | 24 Months |
|---|---|---|
| Best for | Rising income, newer business | Flat, seasonal or uneven income |
| Upside | Isolates your strongest year | Shows stability and longer track record |
| Downside | Swings look larger | Older weak months dilute the average |
| Paperwork | Lighter | Heavier, more accounts and pages |
| If income is falling | Shows the lower recent level | May look better, but trend is reviewed |
| Availability | Offered by most programs | Offered by some programs |
You will read advice online that 24 months earns better terms, and other advice that treats the choice as pure arithmetic. The honest answer is that it varies by program. Some programs overlay or price the shorter window differently, and others do not. Ask your broker to compare the options on actual guidelines instead of guessing from a rule of thumb.
What Does Your Income Trend Say?
Your trend is the best single predictor of which window wins. The numbers below are modeled index values for illustration, not market data. Call the older twelve months 100.
Rising income
Say the older year indexes at 100 and the most recent year at 120. The 12-month average is 120. The 24-month average is 110, which is roughly 8% lower. Choosing 24 months here gives away income for no reason, so 12 months wins as long as the program offers it and you have a full year of self-employment history.
Flat or seasonal income
Picture a landscaper or a short-season hospitality owner whose deposits swing hard from month to month. A 12-month window can land on an unusually strong or weak stretch. The 24-month average changes little when the two years match, and it shows an underwriter the pattern is steady. Seasonal borrowers often prefer 24 months for exactly that reason.
Falling income
Now flip the numbers: the older year at 120 and the recent year at 100. On paper the 24-month average of 110 beats the 12-month figure of 100. But underwriters apply declining-income review and may ask for an explanation, or lean on the lower recent period. A longer window does not erase a downward trend. Lendmire’s piece How to Choose 12 vs 24 Months of Bank Statements After a Down Year walks through that situation in more detail.
This one is a genuine judgment call. A borrower with one bad quarter inside an otherwise strong two years may do better on 24 months, while a borrower whose business has clearly shrunk is better served by a program that matches reality, such as the asset-based paths described below.
Where Does the General Rule Break?
The rising-versus-flat rule holds for most files. These cases bend it.
Under 24 months of history. If you have been self-employed for about a year, you generally cannot use 24 months. The choice is made for you.
The window comes from the program. Bank-statement loans are still verified loans. The CFPB’s Ability-to-Repay guide says lenders must verify the income or assets they rely on, and it does not prescribe 12 or 24 months. So the same statements can produce different qualifying income at different investors.
Commingled accounts. When personal and business money mix in one account, eligible income shrinks under either window, because deposits that cannot be tied to the business get removed.
One-time deposits. A single large deposit, a windfall or a refund can distort an average. Underwriters usually remove it. Do not count on it helping you, and do not be surprised when it vanishes.
Partial ownership. Below 100% ownership, income is prorated to your share. Business statements need at least 25% ownership on the programs in the network.
Hybrid files. A co-borrower with traditional employment income can sometimes be blended with your bank-statement income, depending on the program.
Entity vesting. Holding title in an LLC is a program-by-program question, subject to program terms, so confirm it before you submit.
Reserves are separate. Choosing a statement window does not waive reserves. They are checked independently of how income is proven.
Other documentation routes. A profit-and-loss method, an asset allowance and an assets-only path all exist. The asset allowance divides your liquid assets by 36, 60 or 84 months to create qualifying income. Assets-only needs liquid assets equal to the loan amount plus closing costs, with no debt-to-income test. These routes can fit a borrower whose deposits are lumpy or declining.
How Do the Network Programs Fit In?
Here is where seeing many lenders helps. Lendmire is a broker, so it compares wholesale programs and does not lend itself. Two program families matter for the window choice. The first is a portfolio non-QM bank-statement program. It carries files from $300,000 up to $6,000,000 and takes 12 or 24 months of statements. The second is a bank portfolio jumbo program. It carries files up to $30,000,000, uses 12 months only, and begins above $4,000,000, overlapping the first program up to $6,000,000. So on very large loans the window is often decided by the program.
Through select wholesale programs, subject to full underwriting, leverage on a primary-residence purchase typically steps down with size: up to 90% through $1,000,000, 85% through $2,000,000, 80% through $3,000,000, and 75% at the top credit tier through $4,000,000. Second homes and investment property take their own ladders, so read each figure from the occupancy’s own band. Above $4,000,000 every file is reviewed case by case before submission, and the bank program’s own ladder takes over at 65% through $5,000,000, 60% through $10,000,000 and 55% through $30,000,000, all on review.
Other typical parameters on these programs: a credit-score floor of 660 on the portfolio program, 680 on the bank program, and 700 above the super-jumbo line. Debt-to-income runs up to 50%. Reserves typically run 3 months on loans to $500,000, 6 months to $1,500,000, and 9 months above that. First-time investors generally need 12 months. Guidelines change, and every file is underwritten individually.
One practitioner pattern: borrowers who ask for 24 months because it feels safer often discover their rising income made the 12-month number meaningfully better. The reverse also happens. A broker who runs both sets of numbers before choosing a program saves the borrower from locking into the wrong window.
For investors, the cash-flow path often changes the answer. If your property rents well, a rental-income loan may be a better fit than either window.
Can You Run It Yourself Before You Apply?
A rough worksheet mirrors what a loan officer will do. Use your own statements.
1. List total deposits for each of the last 24 months on every account you plan to use. 2. Strike out loan proceeds, refunds, one-time items and moves of your own money between accounts. 3. Add up the most recent 12 months of what remains and divide by 12. 4. Add up all 24 months and divide by 24. 5. Apply your ownership share, then the expense ratio that fits your business. 6. Compare the two results. If the 12-month figure is higher, check that the recent year is not a one-off. If the 24-month figure is higher, check that your income is not falling. 7. Take both results to your broker and ask which programs offer each window.
If the two numbers are within a few percent of each other, choose the window with the simpler paperwork. If they differ widely, the trend is telling you something, and the larger number deserves a second look before you build a purchase around it.
What Mistakes Hurt a File?
Most problems are preventable.
- Assuming every deposit counts. Loans, refunds, one-offs and your own money moving between accounts are removed.
- Assuming no verification. Bank-statement loans still verify income through your statements.
- Mixing accounts. Run business money through the business account and personal money through the personal one.
- Submitting partial statements. Missing pages stall files.
- Picking 24 months by default. It is not always safer.
- Ignoring overdrafts and returned items. They signal cash-flow stress.
- Treating the window as the only variable. Credit, reserves, property and leverage still decide the file.
Tax treatment can depend on how the funds are used and how the property is held; borrowers should keep clear records and speak with a qualified tax professional before relying on any deduction.
Key Terms Defined
Bank-statement loan: A mortgage that is reviewed around deposits in your accounts instead of traditional personal-income documentation, built for self-employed borrowers.
Qualifying income: The monthly income figure left after ineligible deposits are removed, the average is taken, and the expense ratio is applied.
Expense ratio: The percentage of business deposits treated as operating costs rather than income.
Window: The number of consecutive monthly statements, either 12 or 24, used to calculate income.
DTI (debt-to-income): Your monthly debts divided by your qualifying monthly income.
Reserves: Liquid funds you hold after closing, counted in months of the property payment.
Frequently Asked Questions
Which is better, 12 or 24 months?
Neither is better in general. The winner is whichever window produces the higher income you can fully document. Rising income favors 12 months. Flat or seasonal income favors 24. Have your broker compute both on your actual statements.
Can I choose the window myself?
Usually only within what the program offers. Some programs take either window, while others take only 12 months. Matching you to a program that offers the window you want is part of the broker’s job.
Can I use 12 months with a newer business?
Often yes, and with about a year of self-employment history 24 months may not be available at all. A program may ask for supporting items such as a profit-and-loss statement or an accountant letter.
Does 24 months get better terms?
It varies by program. Some programs treat the windows differently, and others do not. Ask for both options to be reviewed on actual guidelines instead of relying on general advice.
Do investment properties use the same windows?
Bank-statement programs can finance investment property, on their own leverage ladder for that occupancy. A rental-income loan removes the window question altogether, since it is reviewed on the property.
Your Next Step
If you are financing a high-balance property on business or personal bank statements and want to see how the numbers work, Lendmire can help you compare super jumbo bank statement loan options based on your deposits, the property, credit profile, leverage, and your goals. Consumer bank-statement lending runs in 16 states: AL, CA, CO, FL, GA, IN, MI, MT, NM, NC, OH, PA, TN, TX, VA and WA. Nothing here is a commitment to lend, and eligibility is subject to full underwriting.
Whichever window wins, the strongest files are the ones where the deposits tell a clean, consistent story across every month on the page.
Lendmire’s self-employed mortgages page presents both super jumbo programs, bank statement and DSCR, side by side.
About Lendmire
Lendmire is a non-QM mortgage brokerage (NMLS# 2371349) arranging DSCR investor loans in 41 markets, including Washington, D.C. DSCR eligibility is generally reviewed around property-level rental income rather than personal income, subject to lender and program guidelines, a fit for self-employed investors and LLC-owned portfolios. Lendmire was recognized as a Scotsman Guide Top Mortgage Workplace in 2025 and 2026.
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References
1. Scotsman Guide, “Don’t Shut the Door on Quality Borrowers”
2. CFPB Ability-to-Repay and QM Small Entity Compliance Guide
This article is part of Lendmire’s super jumbo bank statement loan program — full qualification details, guidelines, and scenarios live on the program page.
Related reading: How a Luxury Home Bank Statement Mortgage Works · Can 12 Months of Mixed Account Bank Statements Qualify a Super Jumbo Loan? · How a Bank Statement Loan Works for a Penthouse
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
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- Lendmire LLC · Firm NMLS# 2371349 · Verify firm licensure
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.