It often happens that when a couple decide to make Wills they agree on the terms of each Will before giving instructions to the solicitor. If the couple agree that after the first of them dies, that the survivor will not change his or her Will, then the Wills are Mutual Wills. The agreement can be oral or in writing. Often in a second marriage, each spouse may have children from a previous marriage whom they would like to receive part of the estate. The couple agree as to what is to happen when the first of them dies and then when the second of them dies. If there is an agreement and the Wills are signed, then they are Mutual Wills. The agreement can be evidenced in writing usually by signing a Will Contract which sets out the terms of the agreement. Alternatively the parties can sign a statutory declaration to the effect that there is an agreement and that agreement provides that the Wills will not be changed after the first spouse dies.
If there is nothing in writing then the agreement exists however the terms of that agreement may not be known by anyone other than the couple. In the event that the surviving spouse breaches the agreement and changes the Will after the death of his or her spouse, if the existence of the agreement is not known to an affected third party, then that person may be denied the opportunity to enforce the agreement.
It is a complex area of the law however if there is an agreement and Mutual Wills exist then the agreement should be documented to ensure that the intended beneficiaries receive their entitlements.