CTM04510 - Corporation Tax: trading losses - relief against total profits: preceding accounting periods: general
CTA2010/S37,CTA2010/S38,CTA2010/S39
Guidance on relief for trading losses against total profits is at CTM04505. Where the amount of a trading loss exceeds the profits of the same accounting period, the company may claim to carry back the excess against the profits of preceding accounting periods. The preceding accounting periods are those falling wholly or partly within the preceding period.
Losses may be only carried back against profits of a preceding accounting period if the company was carrying on the trade (in which the loss was incurred) at some time in that accounting period. However it is not necessary for the trade to have been carried on for the whole of the preceding accounting period. If the trade was carried on at any time in an accounting period, then losses may be set-off against the profits of the whole of that accounting period.
The preceding period is usually the twelve months preceding the accounting period in which the loss is incurred. A temporary extension to this rule was introducted by FA2009/S23. This extended the loss carry back to 3 years for AP’s ending between 24/11/2008 and 23/11/2010. For further details see BN 13 issued on 22/04/2009.
If a company ceases to carry on a trade, the preceding period is three years preceding the accounting period in which the loss is incurred (CTM04520).
If an accounting period straddles the beginning of the preceding period:
- its profits are apportioned on a time basis, and
- relief is available only for the profits falling within the preceding period.
Profits of later accounting periods comprised in the preceding period are relieved before profits of earlier accounting periods. Accounting periods must be taken in order, most recent first. There are two examples at CTM04540.

