Net Operating Loss (NOL) Carryforward

A net operating loss arises when allowable deductions exceed gross income for a tax year. Rather than wasting the loss, the tax code permits it to be carried to other years and applied against taxable income, smoothing tax liability across a business cycle.

The rules changed substantially with the Tax Cuts and Jobs Act. For losses arising in tax years beginning after December 31, 2017, carrybacks were generally eliminated and carryforwards became indefinite, but the deduction in any carryforward year is limited to 80 percent of taxable income determined before the NOL deduction. Losses generated in earlier years retain their original attributes - a twenty-year carryforward with no percentage limitation - so companies with mixed vintages must track pre- and post-2017 layers separately and apply them in the correct order. The CARES Act temporarily suspended the 80 percent limitation and permitted five-year carrybacks for losses arising in 2018 through 2020, an interlude that still appears in amended returns and carryforward schedules.

The most consequential constraint on acquired losses is Section 382. When a corporation undergoes an ownership change - broadly, a more than 50 percentage point increase in ownership by five percent shareholders over a three-year testing period - the annual use of pre-change losses is limited to the value of the corporation at the change date multiplied by the long-term tax-exempt rate, with adjustments for built-in gains and losses. Because equity financing rounds and acquisitions routinely trigger ownership changes, Section 382 studies are a standard workstream for venture-backed and private-equity-owned companies.

For financial reporting, NOL carryforwards produce deferred tax assets subject to valuation allowance assessment, which links loss tracking directly to the ASC 740 provision.