Sch 3 para 17
(1) The amendments made by paragraphs 11 to 13 of this Schedule have effect in relation to accounting periods beginning on or after the commencement date. (2) For the purposes of sub-paragraph (1), if an accounting period of a company begins before, and ends on or after, the commencement date (“the straddling period”)— (a) so much of the straddling period as falls before that date and so much of that period as falls on or after that date are to be treated as separate accounting periods, and (b) where it is necessary to apportion an amount for the straddling period to the two separate accounting periods, it is to be apportioned on a just and reasonable basis. (3) Subsections (1) to (5) of section 113 of FA 2015 (meaning of “accounting period”) have effect for the purposes of this paragraph as they have effect for the purposes of Part 3 of that Act.