Commentary on Sections Overview Overview Section 229: The additional calculation rule: special cases
844.This section:
	modifies the rule in section 228 if the receipt under calculation arises in respect of part only of the premises subject to the taxed lease; and
	sets limits on the reduction under that section in two cases.
It is based on section 37(2), (3) and (9) of ICTA. The corresponding provision for income tax is in section 289 of ITTOIA.
845.Section 227 extends relief under section 228 to business property receipts treated as arising in relation to the variation or waiver of the terms of a lease. This is reflected in the reference in subsection (2) to section 221. See Change 46 in Annex 1.
846.But subsection (2) does not apply to receipts under section 222 (assignments for profit of lease granted at undervalue) because it is not possible for a lease to be assigned other than in respect of the whole of the premises subject to the lease.
847.Subsection (3) requires the fraction in subsection (2) to be calculated on a “just and reasonable basis”, where section 37(3) of ICTA requires a “just apportionment”. See Change 12 in Annex 1.
848.Subsection (4) restricts the reduction calculated under section 228(4) or subsection (2) of this section to the “unused amount” of the taxed receipt by reference to which it is calculated. That is because giving greater relief would create a conflict with section 235 (limit on reductions and deductions). Source legislation is not as explicit about the way in which relief in relation to a taxed receipt must not exceed the amount of the taxed receipt. See Change 49 in Annex 1.