A tax attribute is an item on a taxpayer’s record that carries from one year into the next and changes how much tax is owed in a future period. The most familiar example is a net operating loss: if a business loses money this year, that loss becomes an attribute it can use to reduce taxable income later. Tax attributes matter most in corporate mergers, acquisitions, and bankruptcies, where their value can rival a company’s physical assets and where federal rules tightly control how much of the benefit a new owner actually captures.
The Three Categories of Tax Attributes
Attributes fall into three broad groups, and the category matters because each follows different rules for transfer, limitation, and expiration.
Loss and deduction carryforwards. Net operating losses, capital losses, and disallowed business interest sit here. They reduce future taxable income directly and are the most commonly monetized attributes in corporate deals.
Credit carryforwards. General business credits, foreign tax credits, and minimum tax credits. Credits reduce the final tax bill dollar-for-dollar rather than reducing taxable income, which makes them more valuable per dollar than a deduction.
Basis and accounting methods. The tax basis of assets, inventory accounting methods like LIFO or FIFO, and accumulated earnings and profits. These do not directly shrink a tax bill, but they set the framework for calculating future gains, losses, and deductions. A company with high-basis assets, for instance, will recognize smaller gains when it sells them.
Common Tax Attributes and How They Work
Net Operating Losses
The net operating loss is the attribute that drives the most deal value and the most IRS scrutiny. An NOL arises when a taxpayer’s deductions exceed its gross income for a year. Under the Tax Cuts and Jobs Act, NOLs generated in tax years beginning after December 31, 2017, carry forward indefinitely, with no expiration date.1Office of the Law Revision Counsel. 26 U.S. Code 172 – Net Operating Loss Deduction Before that change, corporate NOLs expired after 20 years, which created pressure to use them quickly or lose them.
The tradeoff for indefinite carryforward is a ceiling on annual use. For tax years beginning after 2020, post-2017 NOLs can offset only 80% of taxable income in any given year.2Internal Revenue Service. Instructions for Form 172 – Net Operating Losses That guarantees the government collects at least some tax each year, no matter how large the accumulated losses. Pre-2018 NOLs still being carried forward are not subject to the 80% cap and can offset 100% of taxable income. Corporations claim the NOL deduction on line 29a of Form 1120.3Internal Revenue Service. Form 1120 – U.S. Corporation Income Tax Return
Capital Loss Carryovers
When capital losses exceed capital gains for the year, the excess becomes a carryover. Capital losses can only offset capital gains, not ordinary income, which makes them less flexible than NOLs. Corporations carry unused capital losses forward for five years. Individuals carry theirs forward indefinitely, rolling the excess into the next year as either a short-term or long-term loss depending on its character.4Office of the Law Revision Counsel. 26 USC 1212 – Capital Loss Carrybacks and Carryovers That five-year corporate window means capital losses expire far more quickly than NOLs, which can make timing critical in an acquisition.
Disallowed Business Interest
Businesses cannot deduct unlimited interest expense. Under Section 163(j), the deduction for business interest in any year is capped at the sum of the taxpayer’s business interest income plus 30% of its adjusted taxable income. Interest above the cap is not lost; it carries forward to the next year and is treated as if it were paid in that year.5Office of the Law Revision Counsel. 26 USC 163 – Interest For highly leveraged companies, these disallowed interest carryforwards can accumulate into a significant tax attribute. Section 381 specifically lists them as an item that transfers in qualifying corporate acquisitions.6Office of the Law Revision Counsel. 26 U.S. Code 381 – Carryovers in Certain Corporate Acquisitions
Tax Basis
Tax basis is the taxpayer’s investment in a piece of property for tax purposes. It determines two things: how much gain or loss you recognize when you sell the asset, and how much depreciation you can claim while you hold it. A higher basis means larger annual depreciation deductions and a smaller gain on sale. Basis is not a carryforward in the same sense as an NOL, but it functions as a tax attribute because it directly shapes the computation of taxable income in future years. In acquisitions, the question of whether the buyer gets a stepped-up basis (reflecting the purchase price) or a carryover basis (inheriting the seller’s old basis) is one of the most consequential structural decisions.
How Attributes Move (or Don’t) in a Corporate Transaction
Whether a buyer inherits a target’s attributes depends almost entirely on how the deal is structured. In a taxable asset purchase, the buyer acquires the company’s assets, gets a stepped-up basis reflecting the purchase price, and leaves the seller’s NOLs, credits, and other attributes with the selling entity. In a stock purchase, the target corporation continues to exist, and its attributes stay inside it. The buyer owns a company that still has its old attributes, subject to limits.
Tax-free reorganizations and subsidiary liquidations follow a different rule. Under Section 381, the acquiring corporation is required to succeed to the target’s attributes and take them into account going forward. Qualifying transactions include a complete liquidation of a subsidiary into its parent, and Type A (statutory mergers), C, D, F, and G reorganizations. The list of attributes that carry over is extensive: NOLs, capital loss carryovers, earnings and profits, accounting methods, depreciation methods, disallowed business interest carryforwards, and general business credits, among others.6Office of the Law Revision Counsel. 26 U.S. Code 381 – Carryovers in Certain Corporate Acquisitions
The Cap That Follows an Ownership Change
Even when attributes legally survive a transfer, an ownership change triggers a cap on how quickly the new owner can use them. This is the rule that prevents companies from being acquired solely for their tax losses.
An ownership change occurs when the aggregate stock ownership of one or more 5-percent shareholders increases by more than 50 percentage points compared to the lowest ownership percentage those shareholders held at any point during the prior three-year testing period.7Office of the Law Revision Counsel. 26 USC 382 – Limitation on Net Operating Loss Carryforwards and Certain Built-In Losses Following Ownership Change The trigger is broader than it sounds. It catches new equity issuances, redemptions, and sequences of smaller transactions that cumulatively cross the threshold.
Once an ownership change is confirmed, annual use of pre-change losses is capped at the Section 382 limitation: the fair market value of the loss corporation’s stock immediately before the change, multiplied by the IRS-published long-term tax-exempt rate.7Office of the Law Revision Counsel. 26 USC 382 – Limitation on Net Operating Loss Carryforwards and Certain Built-In Losses Following Ownership Change As of early 2026, that rate is 3.58%.8Internal Revenue Service. Rev. Rul. 2026-6 A company valued at $100 million before the ownership change would therefore face an annual cap of roughly $3.58 million in pre-change loss utilization. The government lets you use the losses at a rate reflecting the economic return the acquired company would have earned on its own, not faster.
One scenario drops the limitation to zero. If the new loss corporation does not continue the business enterprise of the old loss corporation at all times during the two-year period following the ownership change, the annual limitation becomes zero.7Office of the Law Revision Counsel. 26 USC 382 – Limitation on Net Operating Loss Carryforwards and Certain Built-In Losses Following Ownership Change That rule stops a buyer from acquiring a loss corporation, shutting down its operations, and using the losses to shelter income from a completely different business.
Attribute Reduction After Debt Discharge
Attributes also come under pressure outside the acquisition context. When a company discharges debt in bankruptcy or while insolvent, the forgiven amount is excluded from taxable income, but the taxpayer pays for that exclusion by reducing its tax attributes.9Office of the Law Revision Counsel. 26 USC 108 – Income From Discharge of Indebtedness The statute sets a fixed order: NOLs of the discharge year and NOL carryovers go first, followed by general business credit carryovers, minimum tax credits, capital loss carryovers, the basis of the taxpayer’s property, passive activity loss and credit carryovers, and foreign tax credit carryovers. Each attribute is reduced dollar-for-dollar (or, for credits, 33⅓ cents per dollar of excluded income) until fully exhausted before the next in line is touched. The reduction is reported on IRS Form 982.10Internal Revenue Service. About Form 982, Reduction of Tax Attributes Due to Discharge of Indebtedness
For companies emerging from bankruptcy, the interaction between Section 108 reduction and the Section 382 cap can be particularly painful. A reorganization in bankruptcy often triggers an ownership change that then caps whatever NOLs survive the Section 108 reduction.
Attributes Individuals Carry
Although the most complex attribute rules apply to corporations, individuals carry attributes too. Capital loss carryovers, passive activity losses that are suspended until the taxpayer generates passive income or fully disposes of the activity, and unused charitable contribution carryforwards all function as tax attributes for individual filers. The stakes are lower in dollar terms, but the mechanics are the same: a past economic event creates a benefit that reduces tax in a future year, subject to specific limitations on when and how much you can use.
For both corporate and individual taxpayers, the core lesson holds. Tax attributes represent real economic value, but that value is never guaranteed. Ownership changes, debt discharges, missed deadlines, and structural missteps in a transaction can all erode or eliminate the benefit. The rules are designed so that tax losses follow real economic activity rather than being traded as standalone commodities, and the IRS enforces that principle aggressively.