Sch 15 para 105
(1) Each of the following is a “pre-acquisition accounting period” of the purchaser— (a) the purchaser's reference accounting period, and (b) each preceding accounting period. (2) Each of the following is a “post-acquisition accounting period” of the purchaser— (a) the first accounting period after the purchaser's reference accounting period, (b) each subsequent accounting period, and (c) each period which is a notional accounting period for the purposes of section 165 or section 416ZA of CAA 2001. (3) See paragraph 106 for provision about accounting periods before the purchaser comes within the charge to corporation tax.