5U.K.After section 51J insert—
“51JASixth restriction: allocation where profits chargeable at NI rate
(1)This section applies if—
(a)section 51B, 51C, 51D or 51E applies, and
(b)the relevant AIA qualifying expenditure for the purposes of the section in question includes expenditure incurred in a low-rate year in respect of an NI rate activity.
(2)For the purposes of this section expenditure is “incurred in a low-rate year” if it is incurred in a financial year for which the Northern Ireland rate is lower than the main rate.
(3)The maximum annual investment allowance that may be allocated under section 51B, 51C, 51D or 51E to AIA qualifying expenditure incurred in a low-rate year in respect of qualifying activities other than NI rate activities is determined by the formula—
where—
A is the amount of the single annual investment allowance that would otherwise be available for allocation;
T is so much of the relevant AIA qualifying expenditure for the purposes of the section in question as is incurred in a low-rate year;
NI is so much of the relevant AIA qualifying expenditure for the purposes of the section in question as is expenditure incurred in a low-rate year in respect of an NI rate activity.”