A carryback claim is a request to apply a loss from your current tax year against income you reported in an earlier year, so the IRS refunds tax you already paid. Under current law the opportunity is narrow: for net operating losses arising after 2020, the general rule is no carryback at all. The exceptions that still produce refunds are farming net operating losses, corporate net capital losses, net section 1256 contracts losses, and certain unused general business credits.
What a Carryback Claim Does
The idea is straightforward. You had taxable income in a prior year and paid tax on it. This year you have a qualifying loss. A carryback lets you treat that loss as if it had occurred in the earlier year, recompute the earlier year’s tax, and collect the difference as a refund. That is different from a carryforward, which uses the loss to reduce tax in a future year instead.
The most common qualifying loss is a net operating loss, which arises when your allowable deductions exceed your gross income for the year. For businesses this usually reflects an operating loss. Individuals can generate an NOL too, but it almost always stems from business activity rather than personal deductions like mortgage interest or charitable giving.
What Losses You Can Still Carry Back
Four categories of losses and credits remain eligible for a carryback refund under current rules.
Farming net operating losses. The portion of your NOL attributable to a farming business can be carried back two years.1Office of the Law Revision Counsel. 26 USC 172 – Net Operating Loss Deduction The farming loss is the lesser of your NOL for the year or the NOL you would have if only farming income and deductions were counted. This is the one meaningful survivor of the TCJA changes for most taxpayers.
Corporate net capital losses. When a corporation’s capital losses exceed its capital gains for the year, the net capital loss can be carried back to each of the three preceding tax years.2Office of the Law Revision Counsel. 26 USC 1212 – Capital Loss Carrybacks and Carryovers Individuals cannot do this. Their capital losses offset up to $3,000 of ordinary income per year, and the rest carries forward only.
Net section 1256 contracts losses. Individuals with losses on certain futures and options contracts can seek a quick refund by carrying the loss back.3Internal Revenue Service. About Form 1045, Application for Tentative Refund
Unused general business credits. Both individuals (on Form 1045) and corporations (on Form 1139) can carry back unused general business credits.4Internal Revenue Service. About Form 1139, Corporation Application for Tentative Refund
What You Can’t Carry Back Anymore
The Tax Cuts and Jobs Act eliminated the general NOL carryback for losses arising after December 31, 2017. The CARES Act temporarily reopened the door for losses arising in 2018, 2019, and 2020, allowing those years a five-year carryback.5Internal Revenue Service. Frequently Asked Questions About Carrybacks of NOLs for Taxpayers Who Have Had Section 965 Inclusions That window has closed. If your NOL arose after 2020 and isn’t a farming loss, you can only carry it forward.
Individuals should also know what the rules don’t offer. There is no carryback for personal capital losses, and ordinary non-farming business NOLs for post-2020 years cannot be carried back regardless of how large they are or how much tax you paid in prior years.
How to File for a Quick Refund
The fastest route to a carryback refund is the tentative refund application. Individuals, estates, and trusts file Form 1045. Corporations file Form 1139. The IRS is required to process these applications within 90 days of the later of the date you file a complete application or the last day of the month that includes the due date, with extensions, of your return for the loss year.6Internal Revenue Service. Instructions for Form 1139 – Corporation Application for Tentative Refund
The deadline for filing either form is 12 months after the end of the tax year in which the loss arose.7Internal Revenue Service. Instructions for Form 1045 A calendar-year taxpayer with a 2025 loss has until December 31, 2026. Miss that and the quick-refund path closes.
Do not submit Form 1045 or 1139 with your current-year tax return; they are separate filings. Form 1045 can now be e-filed using Form 8453-TR as a declaration, and paper filing remains available by mailing the form to the IRS service center listed in your income tax return instructions.7Internal Revenue Service. Instructions for Form 1045
The application has to show the work. Attach a schedule calculating the loss in the loss year, then demonstrate how applying it to each carryback year reduces the taxable income and tax for those years. You will need the original returns for every affected year and will have to recompute each one. The refund you request is the difference between the tax originally owed and the tax owed after the loss is applied. Incomplete applications are a frequent cause of delay, and a request for additional information can eat into the 90-day processing window.
Any refund paid through this process is tentative. The IRS can audit the claim later, and if it determines the refund was too large, you owe the excess back with interest.
If You Miss the 12-Month Window
You can still pursue a carryback refund by filing an amended return — Form 1040-X for individuals or Form 1120-X for corporations. The cost is time: amended returns typically take several months to process rather than 90 days.
The outer deadline is the general refund statute of limitations: the later of three years from the date you filed the return or two years from the date you paid the tax.8Internal Revenue Service. 9Office of the Law Revision Counsel. 26 USC 6676 – Erroneous Claim for Refund or Credit The penalty covers income and employment tax refund claims. Reasonable cause can waive it, but a good-faith miscalculation based on legitimate uncertainty is a narrower defense than it sounds; not knowing the rules changed years ago generally will not qualify. The NOL computation, with every required adjustment, is where errors tend to show up, and where professional help tends to pay for itself.