(1)The conditions in this section are met if—
(a)the person carrying on the trade gives appropriate notice of the change of accounting date to the Inland Revenue (see subsection (2)),
(b)the 18 month test is met (see subsection (3)), and
(c)either condition A or B is met (see subsections (4) to (6)).
(2)Appropriate notice of the change of accounting date is given to the Inland Revenue if (and only if) the notice is given—
(a)in a return under the provision of TMA 1970 that applies to the person carrying on a trade (see section 8, 8A or 12AA of that Act), and
(b)on or before the day on which the return is required to be made and delivered under that provision.
(3)The 18 month test is met if the period of account ending—
(a)with the new accounting date in the tax year in which the change of accounting date occurs, or
(b)if there is no new accounting date in that tax year, with the new accounting date in the first tax year in which accounts are drawn up to the new accounting date,
is not longer than 18 months.
(4)Condition A is that, in the 5 tax years immediately before the tax year in which the change of accounting date occurs, there has been no change of accounting date that counts for the purposes of this condition.
(5)A change of accounting date counts for the purposes of condition A if it results in the basis period for the tax year in which the change occurs ending with the accounting date in that tax year.
(6)Condition B is that—
(a)the change of accounting date is made for commercial reasons (see section 218), and
(b)the notice under subsection (2) sets out the reasons for the change.