Corporation Tax Act 2010 section 309

Accounting periods

Section 309 defines the key accounting period terms used in the ring fence expenditure supplement rules, and explains how periods that straddle 1 January 2006 are split for the purposes of this Chapter.

• The "commencement period" is the accounting period in which a qualifying company sets up and starts its ring fence trade; a "post-commencement period" begins on or after 1 January 2006 and is either the commencement period itself or ends after it; a "pre-commencement period" begins on or after 1 January 2006 but ends before the commencement period.
• A company not within the charge to corporation tax that incurs expenditure is treated as having notional accounting periods, as if it were carrying on a trade consisting of the relevant activities from the date those activities began.
• Where an accounting period straddles 1 January 2006, the portion falling before that date and the portion falling on or after it are treated as two separate accounting periods for the purposes of this Chapter.
• Additional special rules apply to straddling periods and to accounting periods that begin before but end on or after 5 December 2013, with further detail provided elsewhere in this Chapter.