Since the 6th April 2012, if you leave 10% of your total estate to a registered charity the remainder of your estate will only be taxed at 36% and not the usual 40%.
The intention of the government is to encourage further charitable gifts of up to £300 million over the next 3 years. I remain unconvinced that this will actually happen, however, if you are thinking of doing this speak with solicitor or Will writer to make sure your Will takes advantage of these changes.
Each year up to 5,000 people gift part of their estate away to a charity of their choice upon death.