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HMRC internal manual

Inheritance Tax Manual

Succession: Wills: Joint and mutual Wills: Mutual Wills

This is where two or more people each agree to execute a separate Will disposing of their property in a particular way. The terms of each Will are usually identical or very similar and give reciprocal benefits - for instance, a husband, wife or civil partner (IHTM11032) may leave property to each other with the same provision if the other should die before they do.

But this in itself is not sufficient to constitute a mutual Will. There must be an arrangement or agreement to make such Wills (with or without an agreement not to revoke them without the consent of the other(s)).

These Wills are usually made by spouses or civil partners to give effect to agreements between them that, on death, they shall each leave their property to their children. Although any two or more persons may choose to execute mutual Wills.

If there is an agreement to execute a mutual Will and the first person to die has revoked or altered their mutual Will, the other person is released from the obligation not to revoke theirs. They also have the right to sue for damages for breach of contract although the amount is likely to be negligible in most cases.

When the Wills are still unrevoked at the death of the first to die, a constructive trust will arise at that time. This is on the basis that it would be fraudulent for the survivor to revoke because the person who has died executed their Will in accordance with the mutual agreement and can no longer revoke that Will, as they are dead.


Angus and Bella make mutual Wills in which:

  • Angus leaves property to Bella for life with remainder to Claire, and
  • Bella leaves property to Angus for life with remainder to Claire.

On Angus’s death Bella is bound by the arrangement so that on Bella’s death both estates will pass to Claire. This is so, even if Claire dies before Bella, because the trust that arises on Angus’s death is irrevocable.

It may sometimes be difficult to determine what property is subject to the constructive trust. It may be specified within the agreement or the Wills themselves. Otherwise the trust may only cover the property which the survivor receives from the estate of the first to die. Alternatively it may extend to that property and also the property the survivor owned at the time the first person died or even to all the property that the survivor owned when they died.