How to Choose 12 vs. 24 Months of Bank Statements After a Down Year

The Quick Read: The window is usually set by the program, so the first step is finding out which windows a given lender allows, not picking the one you like. Where both are offered, 12 months shows a recent decline directly, while 24 months blends an older, stronger year into the average and often produces higher qualifying income after a down year.

• Falling income shows up under either window. Underwriters look at direction, not only the average.
• Some programs allow both windows and some fix one. Ask for both calculations when both are offered.
• Deposit screening and the expense factor often move the number more than the window does.
• On Lendmire’s network, a bank-statement file starts from 12 months of statements, with the 24-month question depending on the individual lender’s program sheet.
• A rental that covers its own payment may not need personal income documentation at all.

The honest answer on who each option is for: 12 months fits the borrower whose income is flat or rising, or whose weak stretch sits in the older months. 24 months fits the borrower whose dip is short, seasonal or recent, and who has a stronger earlier year to lean on. Neither window hides a downward slope. Both are reviewed subject to lender guidelines.

Side-by-Side

The column below reflects published industry norms, not a promise of what any one lender will do. Scotsman Guide describes the typical bank-statement scenario as 12 to 24 months of statements, with details varying by lender and a preference for consistent monthly deposits.

What Each Window Actually Does

Both windows run the same math. The lender takes eligible deposits, removes what is not income, applies an expense factor on business accounts, multiplies by ownership percentage, and divides by the number of months. The window changes only which months are in the pile and what the divisor is.

Screening comes first. Transfers between your own accounts, loan proceeds, refunds and one-time lumps typically come out. Business deposits take an expense factor set by the lender. Some lenders allow a third-party-prepared profit and loss statement to replace a flat factor. No two programs treat this identically, so treat any single factor you read online as an example, not a rule.

What Counts as a Down Year

A down year is a drop that stands out against your normal swings. Measure it three ways before you apply: year over year, the latest six months against the prior eighteen, and the month-by-month direction. A single bad quarter after steady years looks like a dip. Two or three consecutive weaker quarters look like a trend.

Why it happened matters. A lost client, a one-time equipment purchase, a seasonal shift and a business that is shrinking read very differently. Underwriters may ask for a written explanation and support such as contracts, a CPA letter or a profit and loss statement.

When 12 Months Is the Better Fit

Choose 12 months, where the program allows it, in these situations:

• The weak stretch is in months 13 to 24. The older slump drops out, and the recent year stands on its own.
• Income is rising. A 24-month average drags the newer, stronger figures down.
• The business is young. Some select programs accept a shorter history, though that is program-specific.
• You want a lighter file. Fewer statements means fewer deposits to explain and fewer transfers to source.

The risk is plain. If the recent year is the weak one, 12 months puts the decline front and center. Run it only if the number still works.

When 24 Months Is the Better Fit

Choose 24 months, where offered, in these situations:

• The down year is recent and the prior year was strong. The older year props up the average.
• Your income is seasonal or lumpy. A longer window smooths dips and shows the pattern is normal for your business.
• The dip is short. Two years of history shows a temporary setback rather than a collapse.

The costs: more documentation and a heavier burden to explain deposits. Also, if the older year was the weaker one, 24 months can lower your number.

Decision Matrix

Worked Example in Ratios

Take two years of deposits where the first year was strong and the second year ran well below it. Run on 12 months, the qualifying income reflects only the weak year, so it lands lower. Run on 24 months, the strong year lifts the average, and the figure comes out higher. The gap equals half the difference between the two years, before screening and expense factor. That gap is why some loan officers calculate both and use whichever the program allows and the file supports.

Flip the pattern. If the first year was weak and the second strong, the order reverses and 12 months wins. The math is symmetrical. The program rules decide what you can use.

Slope Matters as Much as the Average

Underwriters can average a 24-month window and still review the trend inside it, so a longer window does not hide a decline. If recent months show a drop, a lender may weight the more recent figures more heavily or ask questions about the change, whichever window the program uses. If your income has slipped lately, expect that conversation and be ready to explain what changed.

What Changes the Number More Than the Window

• Deposit hygiene. Transfers and loan proceeds come out. Move personal money cleanly and keep business and personal flows separate where you can.
• Expense factor. On business accounts, the lender’s factor is a bigger lever than the divisor. A third-party-prepared profit and loss statement can sometimes change it.
• Account type. Business, personal or combined statements are treated differently.
• Ownership percentage. Deposits count only up to your share of the business.
• Completeness. Gaps in the statement period get flagged.

On Lendmire’s network, income comes from deposit averaging with lender expense factors, and a typical file starts from 12 months of statements. Alternate windows follow each lender’s program sheet.

Prepare the File

1. List every account that holds business or personal income for the period.

2. Pull every statement in full, with no missing pages or months.

3. Mark transfers, loan proceeds and one-time deposits so the explanation is ready.

4. Write a short letter on why income dipped and what has changed.

5. Gather support: contracts, a CPA letter or a profit and loss statement.

6. Ask the loan officer to run both windows when the program allows it, then compare the results.

When the Window Is Not Your Choice

Some programs allow both windows and some set one. Some select programs accept as few as three months or a 12-month history for newer businesses. Market surveys report self-employment history of two or more years as standard and one year on select programs. Lendmire’s network figure for the documentation base is 12 months of statements.

Occupancy also changes the paperwork. An owner-occupied purchase or cash-out is a consumer mortgage and carries consumer disclosures. Under CFPB Regulation Z, credit to acquire non-owner-occupied rental property is deemed business purpose, so a bank-statement loan on a rental is handled as business-purpose lending. Owner occupancy of a multi-unit changes the thresholds, as Compliance Alliance explains.

When Waiting or Switching Beats Applying

If the down year is recent and nothing has recovered, a few more strong months can lift a 12-month average. Waiting costs time, so weigh it against your deal.

If the property is a rental, consider whether personal income needs to carry the file at all. A DSCR loan is reviewed primarily on property-level rental income covering the payment, subject to lender guidelines. A down year in your personal deposits does not enter that test. Read Lendmire’s complete DSCR loans guide for how that path works. Programs below 1.00 coverage are available through select lenders in the network, with LTV and terms adjusted.

For a longer walk through the same choice on owner-occupied files, see Lendmire’s piece How to Choose 12 vs 24 Months on a Bank Statement Mortgage.

Leverage and Size on Bank-Statement Files

On select lenders in the network, a primary residence purchase or rate-term refinance runs up to 90% LTV, with stronger files earning the top of the range. An asset-depletion alternative runs to about 80% LTV on a primary residence. Owner-occupied cash-out on a primary or second home runs up to 80% LTV with a fixed expense ratio, or 75% with an accountant-prepared ratio. Investment-property cash-out tops out around 75% LTV. Investment purchase leverage on bank-statement documentation varies by lender. Loan sizes run roughly $125,000 to $3,500,000, with reserves commonly around six months of the housing payment. Everything is subject to lender guidelines and individual underwriting.

Call 828-256-2183 or request a quote. Tax treatment varies; consult a qualified professional.

The Verdict

Pick 24 months when an older strong year can balance a short or seasonal dip. Pick 12 months when the older stretch was the weak one or income is climbing. If the program fixes the window, work on deposits, expense treatment and the written explanation instead. And if the property’s rent covers its payment, check whether a DSCR path removes the question entirely.

For current guidelines and terms, see Lendmire’s bank statement loan programs page.

About Lendmire

Lendmire (NMLS# 2371349) is a mortgage brokerage built around DSCR investor lending, with programs available in 41 markets, including Washington, D.C. DSCR lenders commonly evaluate rental-income coverage instead of personal income paperwork — a practical fit for LLC-owned and multi-property investors. Terms vary by lender, property, leverage, and program. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.

References

1. Scotsman Guide, “Don’t Shut the Door on Quality Borrowers”

2. CFPB, Regulation Z § 1026.3

3. Compliance Alliance, Regulation Z and “Investment” Properties