Finance Act 1998

58 (1) This paragraph applies to a claim or election for tax purposes if—

(a) the event or occasion giving rise to it occurs in one accounting period (the period to which it “relates”), and

(b) it affects one or more other accounting periods (whether or not it also affects the period to which it relates).

(2) If a company makes a claim or election which—

(a) relates to an accounting period for which the company has delivered a company tax return and could be made by amendment of the return, or

(b) affects an accounting period for which the company has delivered a company tax return and could be given effect by amendment of the return,

the claim or election is treated as an amendment of the return.

The provisions of paragraph 15 (amendment of return by company) apply.

(3) Schedule 1A to the [1970 c. 9.] Taxes Management Act 1970 (claims and elections not included in returns) applies to a claim or election made by a company if or to the extent that it is not—

(a) made by being included (by amendment or otherwise) in the company tax return for the accounting period to which it relates, and

(b) given effect by being included (by amendment or otherwise) in company tax returns for the accounting periods affected by it.