(1) Section 396B of the Principal Act is amended in subsection (5) -

(a) by substituting "Subject to paragraph (b), where a company" for "Where a company",

(b) by renumbering the existing provision as paragraph (a) of that subsection, and

(c) by inserting the following after paragraph (a):

"(b)

(i) In this paragraph 'relevant amount' means an amount (not being an amount incurred by a company for the purposes of a trade carried on by it) of charges on income, expenses of management or other amount (not being an allowance to which effect is given under section 308(4)) which is deductible from, or may be treated as reducing, profits of more than one description.

(ii) For the purposes of paragraph (a), where as respects an accounting period of a company a relevant amount is deductible from, or may be treated as reducing, profits of more than one description, the amount by which corporation tax is reduced by virtue of subsection (3) shall be deemed to be the amount by which it would have been reduced if no relevant amount were so deductible or so treated.".

(2) This section applies as respects accounting periods commencing on or after 1 January 2013.