The system of corporation tax used in the UK from 1972 until 1999. Dividends distributed to shareholders were subject to tax, but taxes on company profits collected in advance corporation tax were treated as tax credits at basic rate for investors receiving dividends. Shareholders had the grossed-up value of their dividends treated as taxable income: if the basic rate of tax was t, the grossed-up value of dividends was the amount received multiplied by 1/(1 − t). With basic rate tax already paid, shareholders were liable only for the excess of their own marginal tax rate over basic rate, and could claim refunds if their marginal rate of tax was lower than basic rate or if they were not subject to income tax.