Can Husband and Wife Witness Each Other's Wills?

Many couples make mirror wills together, each leaving the bulk of their estate to the other, often with the same backup beneficiaries such as children if the spouse does not survive. Because they are going through the process together, it can feel natural for one spouse to witness the other's will while the second spouse's own will is being signed nearby.

This is exactly the scenario section 15 of the Wills Act 1837 is designed to catch. If a wife witnesses her husband's will, and she is named as a beneficiary in that will (as is standard in mirror wills leaving everything to the surviving spouse), her own inheritance under that will becomes void, even though the will remains validly executed in every other respect.

Section 15 of the Wills Act 1837 provides that if a person who is a beneficiary under a will, or the spouse or civil partner of a beneficiary, acts as an attesting witness to that will, the gift to that beneficiary is void. The rest of the will remains valid and is treated as properly executed; only the beneficiary's specific gift is lost.

The rule exists to prevent witnesses from having a personal financial stake in confirming that a will was properly signed, since a witness with something to gain has an obvious incentive that could, in theory, affect the reliability of their evidence about the signing.

If a couple make mirror wills and witness each other's, and each is the main beneficiary of the other's will, the practical result can be that neither spouse actually inherits under the will as intended, because each one's gift is voided by the other's witnessing. The estate would then likely pass under whatever the will says should happen if the spouse does not survive, or under the intestacy rules if there is no effective substitute provision.

This is a genuinely serious and completely avoidable mistake. It is often only discovered after death, at exactly the point when it is too late to fix, which is why it is worth being absolutely certain about who is witnessing what before any signing takes place.

The fix is simple: use two witnesses for each will who are not beneficiaries and not married to or in a civil partnership with any beneficiary. For a couple making mirror wills, this usually means finding two other people entirely, such as neighbours, friends, or colleagues, to witness both wills.

It is entirely acceptable, and common practice, for the same two independent witnesses to witness both spouses' wills during the same signing appointment, as long as those witnesses are not beneficiaries of either will and are not married to a beneficiary of either will.

If, unusually, one spouse's will does not leave anything to the other, perhaps because of a specific family arrangement, then the other spouse witnessing that particular will would not trigger section 15, because they would not be a beneficiary of it. This is an unusual situation, though, and it is easy to make an error of judgement about exactly who benefits from what, especially if a will contains discretionary trusts or contingent gifts.

Given how easy the mistake is to make and how serious the consequences are, the safest and simplest practice for any couple is to avoid witnessing each other's wills altogether and use two independent people instead.