If the value of your estate exceeds £325,000 (correct at 29 June 2010) the excess on your estate will be liable for Inheritance Tax at the rate of 40%.
All gifts to charity are currently tax free. This means that money that would otherwise go to the Inland Revenue benefits the charity. In short, you can choose to give a portion of your estate to charity instead of the Inland Revenue.
Unlike gifts to individuals, gifts to charities are exempt from inheritance tax whether made in your lifetime or as a legacy. The 'sliding scale' of tax exemption does not apply - even if you pass away in the same year.