In accounting, carrying something forward means taking a balance that was not fully used or resolved in one reporting period and moving it into the next, where it continues to affect the books or the tax return. The idea shows up in ordinary bookkeeping (last quarter’s ending cash becomes this quarter’s opening cash) and, more consequentially, in tax, where unused losses, credits, deductions, and basis can travel across years under specific rules. Carried forward accounting matters because a single fiscal year rarely captures the full economic picture, and both financial reporting standards and the Internal Revenue Code let certain items roll into future periods rather than expire at year-end.
The mechanism itself is straightforward. At the end of each period, temporary accounts like revenue and expense close out, and their net effect lands in a permanent account, usually retained earnings. That ending balance becomes the opening balance for the next period. The same sequential logic governs ending inventory becoming next period’s beginning inventory, and the remaining book value of a depreciating asset becoming the next year’s depreciation starting point. Financially, though, the carryforwards that move real money are the tax ones.
Net Operating Loss Carryforwards
A net operating loss arises when allowable deductions exceed gross income for the year. For losses arising in tax years beginning after December 31, 2017, the carryforward period is indefinite, meaning the loss never expires.1Office of the Law Revision Counsel. 26 USC 172 – Net Operating Loss Deduction
Indefinite is not unlimited. In any given year, a carried-forward NOL can offset only up to 80% of that year’s taxable income, calculated before the NOL deduction itself. The remaining 20% stays fully taxable.1Office of the Law Revision Counsel. 26 USC 172 – Net Operating Loss Deduction Anything you can’t use because of the 80% cap simply rolls to the next year, where the same limit applies again. The practical effect: a company emerging from heavy losses will still owe some federal income tax in every profitable year, even if its accumulated loss balance far exceeds current income.
The Section 382 Trap After an Ownership Change
If a business with NOL carryforwards undergoes an “ownership change,” Section 382 sharply limits how much of the pre-change loss it can use each year going forward. An ownership change occurs when one or more shareholders holding at least 5% of the stock increase their combined ownership by more than 50 percentage points over a rolling testing period.2Office of the Law Revision Counsel. 26 USC 382 – Limitation on Net Operating Loss Carryforwards and Certain Built-In Losses
Once triggered, the annual amount of pre-change NOL usable against taxable income is capped at the fair market value of the company’s stock immediately before the change multiplied by the IRS’s long-term tax-exempt rate. For ownership changes in mid-2026, that rate is 3.58%.3Internal Revenue Service. Rev. Rul. 2026-7 So a $20 million loss corporation that changes hands at that rate faces an annual Section 382 limit of roughly $716,000, even if it holds $50 million in accumulated NOLs. Unused portions of the annual limit stack onto the next year’s allowance, but the pace of utilization slows dramatically.2Office of the Law Revision Counsel. 26 USC 382 – Limitation on Net Operating Loss Carryforwards and Certain Built-In Losses
This comes up constantly in mergers, acquisitions, and venture rounds. A startup that has burned cash and accumulated large NOLs can inadvertently trigger an ownership change across successive fundraises, and by the time profitability arrives the loss balance may be worth far less than expected.
Capital Loss Carryforwards
When capital losses exceed capital gains for the year, individuals can deduct only $3,000 of the net loss against ordinary income ($1,500 if married filing separately).4Office of the Law Revision Counsel. 26 USC 1211 – Limitation on Capital Losses Anything above that threshold carries forward, and for individuals the carryforward has no expiration. It rolls year after year until fully used.5Internal Revenue Service. Topic No. 409 Capital Gains and Losses
The character of the loss travels with it. A net short-term loss carries over as short-term, and a net long-term loss carries over as long-term.6Office of the Law Revision Counsel. 26 USC 1212 – Capital Loss Carrybacks and Carryovers That distinction changes the actual tax savings, because short-term losses offset short-term gains first (taxed at ordinary rates), while long-term losses offset long-term gains first (taxed at preferential rates). State treatment varies. Some states impose stricter time limits or different annual caps, so the federal indefinite carryforward does not automatically apply on a state return.
Tax Credit Carryforwards
Credits are worth more than deductions dollar for dollar, which makes their carryforward rules especially valuable. A $10,000 credit saves $10,000; a $10,000 deduction at a 21% rate saves $2,100.
General Business Credits
Most business credits, including the research and development credit, fall under the general business credit umbrella of Section 38. When the total credit exceeds tax liability for the year, the excess carries back one year and then forward up to 20 years.7Office of the Law Revision Counsel. 26 USC 39 – Carryback and Carryforward of Unused Credits Credits unused after 20 years are permanently forfeited, so tracking the vintage year of each credit matters. Oldest credits should be applied first.
Foreign Tax Credit
The foreign tax credit, which prevents double taxation on income earned abroad, carries back one year and forward ten.8eCFR. 26 CFR 1.904-2 – Carryback and Carryover of Unused Foreign Tax Because the credit is calculated separately for different categories of income (general, passive, and others), records need to be kept by both category and year of origin.
Adoption Credit
The federal adoption credit is nonrefundable, so any portion above tax liability carries forward for a maximum of five years. Whatever remains after that is lost.9Internal Revenue Service. Adoption Credit
Charitable Contribution Carryforwards
Both individuals and corporations face annual limits on charitable deductions, and both get a five-year carryforward for amounts that exceed those limits.10Office of the Law Revision Counsel. 26 USC 170 – Charitable, Etc., Contributions and Gifts For individuals who itemize, the annual limit is generally 60% of adjusted gross income for cash contributions to qualifying public charities, with lower percentages applying to other types of gifts and organizations. Corporations are limited to 10% of taxable income. In both cases, excess contributions carry forward for up to five succeeding tax years on a first-in-first-out basis, and anything unused after five years expires.
Starting in 2026, itemizers can only deduct charitable gifts that exceed 0.5% of adjusted gross income. Smaller donations no longer generate a deduction at all, which can reduce the amount of contributions reaching the annual ceiling and creating carryforwards in the first place.
One special case: qualified conservation easement contributions by certain farmers, ranchers, and Native Corporations get a 15-year carryforward instead of the standard five.10Office of the Law Revision Counsel. 26 USC 170 – Charitable, Etc., Contributions and Gifts
Excess Business Losses for Non-Corporate Taxpayers
Individuals, partners, and S corporation shareholders face an extra layer of loss limitation before the NOL rules take over. Under the excess business loss rule, aggregate business losses exceeding a set annual threshold cannot offset non-business income like wages, interest, and dividends. For 2026, the threshold is $256,000 for single filers and $512,000 for joint filers.
Business losses above those thresholds get recharacterized as an NOL and carried forward under the standard NOL rules, including the 80% cap. A sole proprietor with $800,000 in business losses and $100,000 in wage income cannot use the full loss in the current year. The excess above the threshold rolls forward and takes the same annual caps as any other NOL. The rule was enacted in the 2017 tax overhaul and has been extended through 2028.
Basis Carryover in Like-Kind Exchanges
Carryforward accounting also applies to the tax basis of property in certain nonrecognition transactions. In a Section 1031 like-kind exchange of real property held for investment or business use, the basis of the original property carries over to the replacement property. Specifically, the basis of the new property equals the basis of the old property, decreased by any cash received and adjusted for any gain or loss recognized on the exchange.11Office of the Law Revision Counsel. 26 USC 1031 – Exchange of Real Property Held for Productive Use or Investment
The gain is deferred, not forgiven. When the replacement property is eventually sold in a taxable transaction, the carried-over basis produces the deferred gain. Failing to track basis correctly through a chain of like-kind exchanges is one of the most common compliance errors the IRS flags and can lead to either overpaying or underpaying by substantial amounts.12Internal Revenue Service. Like-Kind Exchanges Under IRC Section 1031 The same basis carryover logic runs through other nonrecognition transactions, including certain corporate reorganizations and insurance policy exchanges under Section 1035.
Keeping Track of What You Have
The biggest practical risk with any carryforward is losing sight of it. NOLs that never expire are easy to forget about. Credits with 20-year windows lapse because no one flagged them. Capital losses from a bad year a decade ago may never reach a return prepared by a new accountant who wasn’t given the prior history.
Every carryforward balance should be documented with its year of origin, original amount, amount used to date, remaining balance, and expiration date if any. For businesses, that tracking belongs in a formal tax provision workpaper. For individuals, it should live in the preparer’s permanent file and roll through the tax software from one year to the next. Changes in tax preparers, accounting systems, or business ownership are the moments when balances most commonly get dropped, so requesting a complete carryforward schedule during any transition is one of the most valuable protective steps available.