Taxes Consolidation Act 1997 section 399

Losses in transactions from which income would be chargeable under Case IV or V of Schedule D

Section 399 provides relief for companies that incur losses under Case IV or Case V of Schedule D, allowing those losses to be set against income of the same type in the same, earlier, or subsequent accounting periods. It is the corporation tax equivalent of the income tax relief available under sections 383 and 384.

• A Case IV loss may be set off against Case IV income of the same accounting period, with any unrelieved balance carried forward against Case IV income of subsequent accounting periods.
• A Case V loss may be carried back and set off against Case V income of the immediately preceding accounting period of equal length, with any unrelieved balance carried forward against Case V income of subsequent accounting periods.
• Non-resident companies that came within the charge to corporation tax on 1 January 2022 under section 25(2A) may carry forward income tax Case V losses for corporation tax purposes under this section.
• Claims must be made on a timely basis; Case V carry-back claims must be made within two years of the end of the loss period, and no group relief is available for Case IV or Case V losses.