The data, from tax efficiency firm TIME Investments, revealed that 36% of the 500 customers it surveyed had not made plans, despite IHT taking 40% of a qualifying estate.
Last year, HMRC collected a record £4.9billion from IHT, but TIME Investments says good Financial Planning can ensure you do not pay more than is necessary.
Henny Dovland, TIME Investments’ IHT expert said: “Financial Planning needs to be done on an intergenerational rather than individual basis.
“Instead of considering bequeathing assets to children alone, it is worth considering how grandchildren and great-grandchildren can benefit.
“It is an area where expert advice from a financial adviser is needed.”
Adam Newnham DIP PFS, of Vision IFP, added: “Intergenerational planning is becoming increasingly important for many of my clients.
“One case specifically comes to mind which demonstrates the benefits of good planning, both for the adviser and the investor; one of our HNW clients sold her business and was worried about passing as much of the proceeds as possible to her family.
“She used a BR service (from TIME Investments) to immediately reinstate the lost BR and move the sale proceeds out of her estate.
“Her family saw the success of this product and our client’s daughter, who had her own IHT concerns, also chose to use a BR service again with TIME Investments, to provide a solution.
“The result was one happy existing client and one happy new client.”