Publication 536 (2023), Net Operating Losses (NOLs) for Individuals, Estates, and TrustsCorporations generally have the same NOL rules as individuals. The carryback period is two years, carryofrward is 20 years. A 1120X is filed within three years of the due date (including extensions) of the return for the loss year. Alternately, the firm can file a Form 1139 - corporate application for tentative refund.Please note the NOL doesn't include corporate charitable contributions and the DRD goes before calculating the NOL. Source: 2H2023 Becker Regulation text, p. R3-20