Super-tax. This term was first employed in the (English) Income Tax Act, 1918 (8 & 9 Geo. 5, c. 40), s. 4, to denote an additional duty of income tax which was then levied upon incomes of over 2,500l., altered to 2,000l. by 10 & 11 Geo. 5, c. 18, per annum. The duty was at the rate prescribed by Parliament in any year.
By the (English) Finance Act, 1927 (17 & 18 Geo. 5, c. 10), s. 38, super tax has ceased to become charge-able; instead, income tax is charged at a standard rte and persons whose income exceeds a stated amount pay at a higher rate in respect of the excess. The higher tax on the excess is treated as a deferred instalment of income tax and is called SUR-TAX. See ss. 38 and 40 (ibid.).