International tax law distinguishes between an estate tax and an inheritance tax. An inheritance tax is a tax paid by a person who inherits money or property of a person who has died, whereas an estate tax is a levy on the estate (money and property) of a person who has died. However, this distinction is not always observed; for example, the UK's "inheritance tax" is a tax on the assets of the deceased, and strictly speaking is therefore an estate tax.

For historical reasons, the term death duty is still used colloquially (though not legally) in the UK and some Commonwealth countries. For political, statutory and other reasons, the term death tax is sometimes used to refer to estate tax in the United States.