I have had some questions about the difference between mutual Wills and mirror Wills. Both are joint Wills and express the testamentary intentions of two or more people, are jointly executed, and expressed in the one testamentary instrument.
The difference between mirror Wills and mutual Wills is that people who have made the corresponding Wills have agreed that the Wills are not to be revoked in their lifetime without notifying the other party and thereby giving the other party the opportunity to revoke their own will. When one party to the mutual wills agreement dies leaving his or her will unrevoked, the agreement is irrevocable.
The key purpose of mutual Wills is to ensure that property flows to intended, agreed, beneficiaries ensuring that a testator’s property can be enjoyed by another during his or her lifetime, but then passes to a third party, the ‘ultimate beneficiary.’ Where this occurs the survivor will be under an obligation to give effect to the terms of the corresponding will, and the obligation will be enforced by the imposition of a constructive trust.
In order for a Court to establish that Wills are mutual they must find on the balance of probabilities that an express or implied agreement was made between the Will makers not to revoke their Wills. Importantly the fact that two persons simultaneously make wills with mutually similar provisions does not itself establish an agreement not to revoke. Such an agreement can only be established by clear and satisfactory evidence.
A will is by its nature revocable, and may be revoked by among other things the making of a later will. The Doctrine of Mutual Wills is founded on a binding contract between two will makers making corresponding Wills to the effect that neither will revoke their Will, without giving notice to the other.
It is easy to allege such an agreement after the parties to it have both died, and any Court should be very careful in accepting the evidence of interested parties upon such a question. The mere fact that two persons make what may be called corresponding Wills is not sufficient to establish a binding agreement not to revoke them.
If two persons make mutual wills, and agree not to revoke them, a breach of that agreement gives an entitlement to a remedy. The agreement may be clearly expressed, or implied however it is important to identify with precision the nature of the implied promise.
In some cases depending upon the circumstances, it may be proper to conclude that the parties to an agreement to make mutual wills by implication agreed, unconditionally, never to revoke their wills. However especially when all that is relied upon for the implication is the conduct of the parties in making joint wills, the implication cannot be drawn that either party will revoke his or her will without notice to the others.