The standard Inheritance Tax rate is charged at 40% on the part of your estate above your nil rate band, currently £325,000, although gifts between spouses or civil partners will be exempt. Where an individual is a homeowner there is an additional Residence Nil Rate Band available up to a maximum of £175,000. This can be restricted depending upon personal circumstances.
There are additional IHT exemptions and reliefs available, most notably Agricultural Relief and Business Relief which can be available at 100% or 50% on agricultural or business assets. This is a particularly complex area of legislation, and it is important to review the nature of these assets and the structure of your business to ensure they are maintained.