5(1)A person who under paragraph 4 is chargeable to tax for a year of assessment on an amount representing part of an adjustment charge may elect that the amount treated as income arising in that year of assessment should be increased.
(2)The election must be made—
(a)by notice in writing,
(b)to an officer of the Board,
(c)before the 31st January following the year of assessment in question.
(3)The election must specify the amount to be treated as income arising in the year of assessment, which may be any amount up to the whole of the adjustment charge so far as not previously charged to tax.
(4)Where an election has been made, paragraph 4 applies in relation to any subsequent year of assessment as if the original amount of the adjustment charge were reduced by the additional amount treated as arising in the year for which the election was made.