Section 398B | The election
From legislation.gov.uk
(1)The election under section 398A must state the date of the relevant day.
(2)The election must be made—
(a)by notice to an officer of Revenue and Customs, and
(b)during the period of two years beginning with the relevant day.
(3)The election is irrevocable.
(4)All such assessments and adjustments of assessments are to be made as are necessary to give effect to the election.