Reading tax returns as a loan officer means doing two things at once: confirming the return is authentic and belongs to the borrower, then translating the numbers on Form 1040 and its schedules into a stable, recurring income figure you can underwrite. The IRS lets borrowers deduct expenses that never involved writing a check and treats some income as one-time when a lender needs to know whether it recurs. Your job is to bridge that gap.
Confirm the Return Is Real and Belongs to Your Borrower
Start on page one of Form 1040. The name, Social Security Number, address, and filing status have to match the loan application and what credit reporting agencies show. A transposed digit or a mismatched name is worth resolving before you touch the income figures, because you don’t want to build an analysis on a document that doesn’t line up.
Filing status changes the math. A Married Filing Jointly return blends two people’s income and deductions, and you need to determine which portion belongs to the borrower actually applying.
Check who prepared the return. A paid preparer must include a Preparer Tax Identification Number (PTIN) in the signature area.1Internal Revenue Service. Frequently Asked Questions: Do I Need a PTIN Self-prepared returns carry a “Self-Prepared” notation instead.
Whenever anything on page one doesn’t reconcile, order an IRS transcript through Form 4506-C. The request runs through the Income Verification Express Service (IVES) and pulls the return data straight from the IRS.2Internal Revenue Service. Income Verification Express Service (IVES) Comparing the borrower’s copy against the transcript is one of the more reliable fraud-detection steps you have, because it catches returns that were altered to inflate income after filing.
Pull Qualifying Income From Form 1040
Adjusted Gross Income on line 11 is the anchor.3Internal Revenue Service. Adjusted Gross Income It’s also a mix of income types that get different treatment in underwriting, so work down lines 1 through 9 and sort them.
Line 1 is W-2 wages and salary, the most dependable income for a traditionally employed borrower. Taxable interest on line 2b and ordinary dividends on line 3b usually stay out of qualifying income unless the borrower shows a consistent history of receiving similar amounts, typically over the prior two years. Lines 4 and 5 — IRA distributions and pensions — need a closer look. A one-time rollover from one retirement account to another is not ongoing income. Recurring monthly pension payments generally are.
Social Security benefits, tax-exempt bond interest, and certain other non-taxable income get special treatment. Because no federal tax comes out of them, the borrower keeps more of every dollar, so lenders may gross the amount up by as much as 25 percent to reflect its higher effective value. Two thousand dollars a month in non-taxable Social Security can count as $2,500 for qualifying purposes. Document that the income is genuinely non-taxable and ongoing before applying the adjustment.
Rebuild Cash Flow on Schedule C
Sole proprietors report business income and expenses on Schedule C, with net profit or loss landing on line 31. That tax figure often understates real cash flow because the tax code lets the borrower deduct expenses that didn’t cost cash. Fannie Mae’s Cash Flow Analysis (Form 1084) gives you a standardized worksheet for the add-backs.4Internal Revenue Service. 2025 Instructions for Schedule C (Form 1040)
The main add-backs on Schedule C:
- Depreciation on line 13. The annual write-off for equipment, vehicles, and other property. No cash left the business, so the full amount comes back to income.
- Depletion on line 12. Same logic, applied to natural resources like oil, gas, or timber.
- Business use of home on line 30. Covers a share of the borrower’s mortgage, utilities, and insurance for a home office. Those housing costs exist either way, so the deduction returns to the income total.
- Amortization and non-recurring casualty losses. Amortization spreads the cost of intangibles like patents or goodwill over time without any cash outflow. A casualty loss is a one-time event that doesn’t reflect normal cash flow.5Fannie Mae. Cash Flow Analysis (Form 1084)
Vehicle and Meal Adjustments
Part IV of Schedule C reports total business miles driven. If the borrower took the IRS standard mileage rate, which is 72.5 cents per mile for 2026, part of that rate is embedded vehicle depreciation.6Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents Per Mile, Up 2.5 Cents Multiply business miles by the year’s depreciation factor and add that back.5Fannie Mae. Cash Flow Analysis (Form 1084) If the borrower instead deducted actual vehicle expenses on line 9, add back only the depreciation component inside those actual expenses.
Business meals on line 24b work the other direction. The IRS caps the deduction at 50 percent of what the borrower spent, so the Schedule C profit already reflects only half the cost. Real cash out the door was double the deducted amount. Subtract the non-deductible half from qualifying income to show the full impact.
Handle Rentals and Pass-Through Income on Schedule E
Schedule E carries two categories that get treated differently: rental real estate in Part I and partnership or S-corporation income in Part II.7Internal Revenue Service. Instructions for Schedule E (Form 1040)
Rental Real Estate
Part I shows income and expenses for each property, with total profit or loss on line 26. Depreciation on line 18 is non-cash and gets added back. Amortization on the rental side follows the same logic and comes back as well.
Then compare adjusted rental income against the full monthly housing cost for that property, meaning principal, interest, taxes, insurance, and any association dues (PITIA). If adjusted rental income exceeds PITIA, the surplus goes into qualifying income. If it falls short, the shortfall becomes a monthly obligation on the debt side.
Partnerships and S-Corporations
Part II reports the borrower’s share of partnership or S-corporation income or loss as shown on the Schedule K-1 each entity issues. Look for recurring patterns over at least two years. Strip out one-time capital gains, non-recurring items, and asset sales so a single good year doesn’t inflate the borrower’s earning power. Only the ordinary, ongoing share of business income belongs in the qualifying figure.
Read the Business Return When the Borrower Owns the Business
When a borrower has a meaningful ownership stake, the personal return alone isn’t enough. Request the business’s own return — Form 1065 for a partnership or Form 1120-S for an S-corporation — along with the borrower’s Schedule K-1.8Fannie Mae. Income or Loss Reported on IRS Form 1065 or IRS Form 1120S, Schedule K-1 Reconcile what the K-1 reports against the overall business picture.
Start with ordinary business income on page one, then apply the same non-cash add-backs used on Schedule C — depreciation, depletion, and amortization — scaled to the borrower’s ownership percentage.5Fannie Mae. Cash Flow Analysis (Form 1084) For a partnership, include guaranteed payments to the borrower when there’s a two-year history of receiving them.
Then check whether reported profits actually reach the borrower. A company that looks profitable on paper but distributes little cash to its owners may not have the liquidity to support new debt. Schedule L, the balance sheet, shows whether the business holds enough liquid assets to keep operating while paying out to owners. If distributions consistently run well below reported profits, use the lower figure.
C-Corporations
A C-corporation (Form 1120) is its own taxpayer. Profits belong to the business, not to the owner, unless they leave as salary or dividends. Count the W-2 salary the borrower draws from the corporation. Dividends can be included if there’s a documented two-year history. Retained earnings sitting inside the corporation generally cannot be counted as personal income, even when the borrower owns 100 percent of the company.
Average Two Years and Watch the Trend
For any income that fluctuates — self-employment, rental, partnership distributions, investment income — plan on two years of returns. Add the qualifying income from both years and divide by 24 to get a monthly average.
Direction matters as much as the average. Rising income year over year makes the two-year average conservative and fair. Declining income calls for a harder look. A meaningful downward trend can push you to use only the most recent, lower year rather than the two-year figure, because the average would overstate where the borrower is actually heading. A steep enough decline can disqualify the income entirely if you can’t establish that it will stabilize.
Borrowers with less than two years of self-employment or pass-through income face more scrutiny. You’ll typically need at least one documented year plus strong evidence the income will continue, such as a signed contract, a professional license in a high-demand field, or verifiable industry experience.
Match the Return to the Application Date
The tax year required depends on when the loan application is dated. From October 15 of the prior year through April 14 of the current year, the most recent year’s return is required, and a filed extension is not a substitute.9Fannie Mae. Allowable Age of Credit Documents and Federal Income Tax Returns After April 15, if the borrower filed an extension using IRS Form 4868, you may be able to work from the prior year’s return while the current filing is pending — but confirm the extension with an IRS transcript pulled through Form 4506-C.
When the IRS announces a filing deadline extension after a natural disaster or similar event, the date windows shift for eligible borrowers. The transcript comparison stays essential regardless of timing.
Turn the Income Figure Into a DTI
Everything above feeds one number: the debt-to-income ratio. DTI compares total monthly debt obligations, including the proposed mortgage, against total monthly qualifying income. For manually underwritten conventional loans the standard maximum DTI is 36 percent, stretching to 45 percent for borrowers with strong credit and cash reserves. Loans run through automated underwriting can qualify with a DTI as high as 50 percent.10Fannie Mae. Debt-to-Income Ratios
Court-ordered alimony, child support, and separate maintenance payments extending beyond ten months count as recurring monthly debts.11Fannie Mae. Monthly Debt Obligations Voluntary payments do not.