More than 60 per cent of people over the age of 50 have not sought advice about inheritance tax (IHT) planning, according to Leeds & Holbeck Building Society.
The new research has also shown that only a quarter (26 per cent) of people questioned nationally were able to correctly identify the IHT threshold as £263,000.
UK's eighth largest building society points out that with the ongoing boom in the housing market the need for IHT planning is now more necessary than ever.
"It is staggering just how many people could now be liable for inheritance tax, given the recent boom in the housing market," said Bob Mottershead, the head of Leeds & Holbeck Financial Services.
He reminds people that although they may not have been liable for IHT a couple of years ago things may very well have changed and therefore people "need to take action or potentially face IHT liabilities."
Gordon Brown increased the level of IHT by three per cent earlier in the year, but in 2003 alone the average national increase in house price was 15.6 per cent and it's expected to rise another 15 per cent throughout 2004.
With rising property values, many estates are being forced above the £263,000 IHT threshold, potentially leaving family members or beneficiaries liable to a 40 per cent inheritance tax bill.
Mr Mottershead concluded: "The majority of people with average or above average value houses may now find themselves above the IHT threshold, but expert advice and estate planning can help to minimise this."DeHavilland Information Services plc