Some 12-13 percent of all homeowners now have an inheritance tax liability due to an increase in the value of their homes. The rise in house prices over the past five years means that there has been a three-fold increase in the number of properties over the inheritance tax (IHT) threshold of £275,000. A major lenders calculation shows that the IHT threshold of £275,000 pounds would now be £406,600 pounds if it had been increased in line with house price inflation over the past 10 years.