(1)For the purposes of this Part a tax is a “qualifying domestic top-up tax” if it is—
(a)domestic top-up tax (see Part 4), or
(b)specified in a regulations made by the Treasury.
(2)A tax may only be specified in regulations if the Treasury consider that it is equivalent in substance to domestic top-up tax (see Part 4).
(3)A tax may be considered equivalent to domestic top-up tax despite being not being calculated in accordance with the financial accounting standard used in the consolidated financial statements of the ultimate parent if calculated in accordance with an authorised accounting standard that is either—
(a)an acceptable accounting standard, or
(b)another financial accounting standard that is adjusted to prevent material competitive distortions.
(4)Regulations under this section may provide that the specification of a tax is to have effect from a time before the regulations are made (but may not provide that the specification of a tax previously specified ceases to have effect before the regulations are made).