A new survey reveals that thousands of people who are relying on their inheritance to fund future commitments such as paying off their mortgage, have not taken the government's inheritance tax into account.

17% of Britons (over 7.9 million people) are anticipating an inheritance but one in five of these (1.6 million people) has no idea that part of it would be liable to the 40% tax.

The research from Brewin Dolphin, also reveals that the majority (53%) of Britons who intend to leave money to relatives and friends – some 9.4 million people nationwide – have not conducted any planning to mitigate the cost of inheritance tax (IHT) either.

Last year alone the government received £2.9 billion through IHT, capitalising on the lack of awareness about this tax amongst the public. Inheritance tax is levied at 40% of any estate worth more than £263,000 – the current threshold.

Regionally the Scots are the worst at IHT planning with 62% of them not taking any preventative action. Single people also fared poorly – over two thirds (67%) failed to do any planning compared with 57% of married couples. The survey shows that the best at IHT planning tend to be divorced or separated people with only 40% having failed to address this.

Of those expecting an inheritance spoken to, the Scots were again the least aware about the IHT threshold with 60% admitting to being unaware of the threshold. The most aware were those living in Greater London, Wales and the West (92%).

Charlotte Black, Marketing Director at Brewin Dolphin said: "Rising house prices have meant that it's no longer the rich who are being hit with this stealth tax. Families with modest assets are being drawn into the net. Indeed, there are an estimated 2.4 million homes across the UK that are now valued above the £263,000 threshold, before taking any other assets into account."

"Coming on top of tax on earnings and investments, IHT is an unpalatable third tax that should be reformed. In a general election year all political parties should note that IHT is a major issue, as it is now penalising millions of Britons."

Although the threshold has been raised by 22% since 1997, it has fallen way behind the 120% growth in house prices during the same period.

"If the government had increased the IHT free threshold in line with house price increases since 1997, it would now be around £450,000. This would ease the financial burden faced by bereaved families. Nevertheless, much can be done to mitigate the cost of IHT such as family trusts and transferring assets within a family. The minimum everyone should do is to make a will," said Charlotte.