The UK used to have marginal tax rates of 102 percent and 95 percent.

True: historical UK tax records show a top marginal rate of about 95% at some point (for example 1970s earned income including surcharge, or wartime) and an effective marginal rate of about 102% (for example 1940s income tax plus surtax, or the 1970s investment income surcharge combined with other charges). Mostly true: both rates existed, but in a slightly different form (for example combined effective rates rather than a single statutory rate), or one figure is slightly off (such as 98% instead of 102%). Mixed: only one of the two rates is supported. Mostly false: the rates were never reached as stated, but similar high rates existed (for example 83–98%). False: UK marginal rates never approached these levels.

Set before the research began.

1. E1 History of taxation in the United Kingdom - Wikipedia Wikipedia · 12 January 2011

   “With the investment income surcharge, this raised the top rate on investment income to 98% – the highest permanent rate since the war.”

2. E2 History of taxation in the United Kingdom - Wikipedia Wikipedia · 12 January 2011

   “The highest rate of income tax peaked in the Second World War at 99.25%.”

3. E3 History of taxation in the United Kingdom - Wikipedia Wikipedia · 12 January 2011

   “A surcharge of 15% kept the top rate on investment income at 90%.”

4. E4 Income Tax and Top Incomes over the Twentieth Century Hacienda Pública Española / Revista de Economía Pública (Instituto de Estudios Fiscales), by A. B. Atkinson, Nuffield College, Oxford · 2004

   “The top rate on investment income in the UK was cut from 98% to 75% in 1979, from 75% to 60% in 1984, and from 60% to 40% in 1988.”

The evidence documents top UK rates of 98% on investment income [E1][E4] and 99.25% in the Second World War [E2], close to the 102% figure, but no evidence item documents a 95% rate. The evidence therefore cannot settle whether both rates existed (mostly true) or only one is supported (mixed).