In general terms, an individual's estate is the total of all their assets, less all their liabilities.
For inheritance tax (www.practicallaw.com/3-382-5648) (IHT) purposes, an individual's estate is the aggregate of all the assets to which they are beneficially entitled, less all their liabilities. The definition includes assets held in a trust in which the deceased had an immediate post-death interest (www.practicallaw.com/8-382-5636), a disabled person's interest (www.practicallaw.com/8-382-5622), or a transitional serial interest (www.practicallaw.com/0-382-7984). However, the estate of an individual immediately before their death does not include excluded property (www.practicallaw.com/4-382-5624). (Section 5, Inheritance Tax Act 1984.)
Assets outside an individual's estate may also be subject to IHT on their death, see Practice note, Deceased's estate: how to value assets and liabilities of the estate for inheritance tax purposes: overview: what is an asset of the estate? (www.practicallaw.com/3-383-6784).