Section 357BLF | Meaning of the “relevant period” etc
From legislation.gov.uk
(1)Subsections (2) to (6) define “the relevant period” for the purposes of sections 357BLB to 357BLE.
(2)The “relevant period” is the period which—
(a)ends with the last day of the accounting period, and
(b)begins on the relevant day or such earlier day as the company may elect.
This is subject to subsection (6).
(3)The “relevant day” is 1 July 2013 in a case where—
(a)the accounting period begins before 1 July 2021, and
(b)the company is a new entrant (see section 357A(11)).
(4)The “relevant day” is 1 July 2016 in any other case.
(5)A day elected under subsection (2)(b) must not be more than 20 years before the last day of the accounting period.
(6)If the last day of the accounting period is, or is after, 1 July 2036 the “relevant period” is the period of 20 years ending with that day.
(7)Expenditure incurred by the company is to be treated for the purposes of sections 357BLB to 357BLD as incurred during the relevant period if (and only if) the expenditure is allowable as a deduction in calculating for corporation tax purposes the profits of the trade for an accounting period which falls, in whole or in part, within the relevant period.