315Supplement in respect of a pre-commencement accounting periodU.K.
(1)If—
(a)a qualifying company incurs qualifying pre-commencement expenditure in respect of a ring fence trade, and
(b)the expenditure is incurred before the commencement period,
the company may claim supplement under this section (“pre-commencement supplement”) in respect of one or more pre-commencement periods.
(2)Any pre-commencement supplement allowed on a claim in respect of a pre-commencement period is to be treated as expenditure—
(a)which is incurred by the company in the commencement period, and
(b)which is allowable as a deduction in calculating the profits of the ring fence trade for that period.
(3)The amount of the supplement for any pre-commencement period in respect of which a claim under this section is made is the relevant percentage for that period of the reference amount for that period.
(4)If the pre-commencement period is a period of less than 12 months, the amount of the supplement for the period (apart from this subsection) is to be reduced proportionally.
(5)Sections 316 to 319 have effect for the purpose of determining the reference amount for a pre-commencement period.