A loss in business is what you have when your total expenses for a period come out higher than your total revenue, leaving a negative number at the bottom of the income statement. That negative figure is the starting point for a stack of federal tax rules that decide how much of the loss you can actually deduct, when you can use it, and what kind of income it can offset. A single loss year is common and often unremarkable; the tax treatment is where things get complicated.
Net Loss in Plain Terms
Subtract every cost your business incurred during an accounting period from every dollar it brought in. If the result is negative, that’s your net loss. It sits at the bottom of the income statement after cost of goods sold, operating expenses, interest, taxes, and any non-operating items have been taken out. On the statement itself, the number typically appears in parentheses or with a minus sign.
A loss year does not mean the business is failing. Companies routinely post losses during expansion, seasonal slumps, or years with heavy capital investment. What matters is whether the losses keep repeating without a clear path back to profit. That pattern, more than any single year, is what suggests the underlying business model needs work.
Operating Losses and Capital Losses Are Not the Same
Two different kinds of losses can come out of a business, and they follow different tax rules.
An operating loss means revenue from selling your goods or services did not cover the ordinary costs of running the business: payroll, rent, utilities, supplies, insurance. It’s a statement about the core business model. A restaurant that spends more on ingredients, staff, and lease than it collects from diners has an operating loss regardless of anything else happening on its balance sheet.
A capital loss happens when you sell a business asset for less than what you paid for it. Equipment, real estate, vehicles, and investment securities can all produce capital losses. The loss is the sale price minus the cost basis, adjusted for depreciation. For individuals, net capital losses beyond what can be offset against capital gains are generally deductible only up to $3,000 per year, with the rest carried forward.
What Drives a Business Into a Loss
Several expense categories combine to push the bottom line negative. Which ones are doing it tells you whether the problem is structural or short-term.
- Cost of goods sold: the direct costs of producing what you sell, including raw materials, manufacturing labor, and inbound shipping. A jump in materials pricing can create a loss even when sales volume holds steady.
- Fixed operating expenses: rent, insurance, salaried staff, loan payments. These hit every month regardless of revenue, which is why they often drive losses during a downturn.
- Variable costs: marketing, sales commissions, and other spending that moves with activity. Over-spending on customer acquisition without enough return is a common path to a loss.
- Interest expense: payments on business debt. A heavily leveraged business can be profitable on operations and still post a net loss after interest.
- Depreciation and amortization: non-cash expenses that spread the cost of long-lived assets over their useful life. They reduce reported income without cash leaving the account, which is why a business can show a loss on paper while cash flow is positive.
Where a Loss Shows Up on Your Taxes
The income statement, sometimes called the profit and loss statement, is where the loss figure lives for financial reporting. Revenue sits at the top, expense categories subtract in sequence, and net income or net loss is the last line.
For tax filing, the form depends on how the business is organized. Sole proprietors and single-member LLCs report income and losses on Schedule C with Form 1040. Partnerships file Form 1065 and pass each partner’s share through on Schedule K-1. S corporations file Form 1120-S with a similar K-1. C corporations report on Form 1120.1Internal Revenue Service. 2025 Instructions for Form 1120 – U.S. Corporation Income Tax Return The entity type affects both how much of a loss you can deduct and when.
How the Tax Deduction Actually Works
When allowable business deductions exceed gross income for the year, the result is a net operating loss, or NOL. You can carry that NOL forward to future tax years and use it to reduce taxable income once the business is profitable again. For NOLs arising in tax years beginning after 2017, the deduction in any given future year is capped at 80 percent of that year’s taxable income calculated without the NOL deduction.2Office of the Law Revision Counsel. 26 USC 172 – Net Operating Loss Deduction The remaining 20 percent of income is taxed no matter how large the carryforward balance is. Carryforwards do not expire.
Before the Tax Cuts and Jobs Act of 2017, businesses could carry NOLs back two years and get a refund of previously paid tax. That option is gone at the federal level for most businesses, with narrow exceptions for certain farming operations and insurance companies.2Office of the Law Revision Counsel. 26 USC 172 – Net Operating Loss Deduction A startup posting losses in its early years cannot get immediate cash back from the IRS. It has to wait for profitable years to use the deduction.
The Limits That Apply Before You Get the Deduction
If you own a stake in a partnership, an S corporation, or a sole proprietorship, you might expect every dollar of business loss to flow to your personal return. It doesn’t. Federal law puts a series of hurdles in the way, and they apply in order. Losses that fail a step are not permanently lost; they carry forward until the limitation is satisfied. But they don’t help you this year.
Basis
Your deductible share of a partnership loss cannot exceed your adjusted basis in the partnership interest. Anything above that carries forward until your basis is high enough to absorb it.3Internal Revenue Service. New Limits on Partners Shares of Partnership Losses Frequently Asked Questions S corporation shareholders face a parallel rule: losses are deductible only up to stock basis plus the basis of loans the shareholder personally made to the corporation.4Internal Revenue Service. S Corporation Stock and Debt Basis Guaranteeing a bank loan to the S corporation does not increase debt basis. You have to lend the money yourself.
At-Risk
Even with enough basis, you can deduct losses only up to the amount you are personally at risk in the activity. That means cash and property you contributed, plus borrowed amounts for which you are personally liable or which you secured with other property as collateral.5Office of the Law Revision Counsel. 26 U.S. Code 465 – Deductions Limited to Amount at Risk Nonrecourse loans generally do not count, and neither do amounts covered by stop-loss agreements or guarantees from related parties.
Passive Activity
Losses from a business activity in which you do not materially participate are classified as passive. Passive losses can only offset passive income; they cannot reduce wages, interest, or income from an active business.6Office of the Law Revision Counsel. 26 U.S. Code 469 – Passive Activity Losses and Credits Limited Material participation generally means regular, continuous, and substantial involvement, with specific IRS tests including the common one of more than 500 hours during the year. Rental activities are automatically treated as passive with limited exceptions.
Disallowed passive losses carry forward. When you eventually sell your entire interest in the activity in a fully taxable transaction, the accumulated suspended losses are released and become deductible against any kind of income.6Office of the Law Revision Counsel. 26 U.S. Code 469 – Passive Activity Losses and Credits Limited
Excess Business Loss
Non-corporate taxpayers face one more limit. For 2026, total business deductions from all sources cannot exceed total business income plus $256,000, or $512,000 on a joint return.7Office of the Law Revision Counsel. 26 USC 461 – General Rule for Taxable Year of Deduction Anything above that is not deductible this year. It converts into an NOL carryforward and becomes subject to the 80-percent-of-income cap in future years. The rule applies through tax year 2026 and is scheduled to expire after that, though Congress could extend it.
Situations That Can Cost You the Deduction
When the IRS Calls It a Hobby
If the IRS treats your activity as a hobby rather than a business, you cannot deduct losses against other income. The IRS presumes an activity is for profit if it shows a net profit in at least three of the last five tax years, or two of seven for horse breeding, training, showing, or racing.8Internal Revenue Service. Is Your Hobby a For-Profit Endeavor? Failing that test does not automatically make the activity a hobby, but it shifts the burden onto you to prove a genuine profit motive. The IRS looks at whether you keep professional records, whether you have changed your approach to try to become profitable, and whether you depend on the activity for a living. Years of losses with no change in strategy invite scrutiny.
Zero Self-Employment Tax, Zero Social Security Credits
A sole proprietor or partner whose business posts a net loss generally owes no self-employment tax for the year, because that tax is calculated on net earnings from self-employment.9Internal Revenue Service. Topic No. 554, Self-Employment Tax The downside is that zero net earnings also means zero Social Security credits for the year. A run of loss years shrinks your future benefits. The IRS offers optional methods on Schedule SE that let you report a small amount of self-employment income in a loss year to keep building credits.
Penalties for Overstated Losses
Inflating a loss to shrink your tax bill draws penalties. The accuracy-related penalty for negligence or disregard of tax rules is 20 percent of the underpayment, rising to 40 percent for gross valuation misstatements and 50 percent for overstated charitable contribution deductions.10Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments If the IRS determines fraud, the penalty jumps to 75 percent of the underpayment attributable to the fraud under a separate provision.11Office of the Law Revision Counsel. 26 U.S. Code 6663 – Imposition of Fraud Penalty Detailed records of every expense, receipt, and business purpose are the most reliable defense in an audit. The gap between a 20 percent penalty and a 75 percent penalty often turns on whether the IRS reads the error as careless or intentional.
State Rules Are a Separate Question
Federal NOL rules are only part of the picture if your business operates in a state with an income tax. Most states allow NOL carryforwards, but the terms vary. Carryforward periods run anywhere from five years to unlimited, and several states cap the dollar amount you can deduct in a single year regardless of the carryforward balance. States that impose gross receipts taxes rather than income taxes generally do not offer NOL deductions at all. A business operating in multiple states applies each state’s rules separately to the income and losses allocated there, which can leave you with a usable carryforward in one state and a fully expired one in another.