The number of estates paying death duties is set to double over the next five years.
Figures published alongside the Budget last night by the Office for Budget Responsibility showed tax receipts gleaned from death duties rising every year until at least 2027.
According to its forecasts, inheritance tax receipts will rise from £5.1bn in 2019-20 to £6bn in 2021-22, then up to £6.8bn in 2024-25 and will rise to £7.6bn in 2026-27.
Last year a total of 25,400 estates had to pay inheritance tax, but the OBR expects this figure to rise to 47,700 by 2026.
The £325,000 inheritance tax allowance has not risen since 2009, which means an increasing number of estates are caught out as their investments, income and savings rise with inflation.