Mirror wills: what they are and when couples use them

What are mirror wills?

Mirror wills are two wills, one for each partner, that say essentially the same thing with the names swapped over. In the most common pattern each of you leaves everything to the other, and the will then names who inherits if your partner has already died, which is usually your children or another agreed group of people, so that whichever of you dies second, the estate ends up in the same place. The Law Commission's 2017 consultation paper on making a will uses exactly this example, describing wills that leave property to the spouse and then to any children.

Although they are drafted together, each mirror will is a separate legal document, signed and witnessed in its own right, which deals only with the property of the person who made it. That separateness is what makes them simple, and it is also why they suit couples whose wishes genuinely match and who trust the survivor to carry out the plan they made together, because nothing in either will obliges the other partner to keep to it.

Can a mirror will be changed after one partner dies?

Yes. A mirror will does not bind the survivor, so once the first partner has died, the person left can make a new will leaving their estate, including everything they inherited from the first partner, to anyone they choose. The Law Commission's consultation paper makes the point directly, explaining that mirror wills do not ordinarily bind the survivor, who remains free to change their will. Either of you can also change your own will at any time whilst you are both alive, without needing the other's agreement.

For many couples that freedom is the whole attraction, because the survivor may live for decades after the first death and needs to be able to respond to whatever happens in that time. The same consultation paper records that some people believe they have a binding arrangement when in fact they have mirror wills, which is why it helps to talk openly about what your wills do and do not promise.

What are the risks of mirror wills?

The main risk is that the plan you made together is only as secure as the survivor's later decisions, and those decisions can be shaped by events neither of you can foresee. The situations that tend to cause problems are these.

• The survivor remarries. Under section 18 of the Wills Act 1837 marriage revokes an existing will, so unless the survivor makes a new one, their estate passes under the intestacy rules, which give a new spouse the personal possessions, a fixed sum and half of anything above it, so the survivor's own children receive at most half of the remainder and nothing at all if the estate is below the fixed sum. Our guide to the intestacy rules sets out the full order.

• The survivor changes their mind. A new will can leave out people you both meant to benefit, which is the outcome blended families worry about most, because children from an earlier relationship depend entirely on the survivor's goodwill.

• The money is spent. Whatever you leave outright to your partner becomes theirs to spend or give away, so the amount left for your children at the end may be much smaller than either of you expected.

• You die together. Where it is uncertain who died first, section 184 of the Law of Property Act 1925 presumes the younger survived the elder, which makes little difference when both wills end with the same people but can send everything to one side of the family when they do not.

None of this makes mirror wills a poor choice, because many couples are content to accept these risks in return for leaving the survivor in full control. It does mean the decision is worth making deliberately rather than by default.

Mirror wills vs mutual wills: what is the difference?

Mutual wills are matching wills made under a binding agreement that the survivor will not change the arrangement after the first death, whereas mirror wills carry no such promise. The Law Commission's consultation paper explains that mutual wills need wills made under an agreement that binds the survivor, followed by the death of the first partner. Making mirror wills at the same time in similar terms is not enough on its own, and although the agreement can be proved by evidence outside the wills, the paper regards an express statement in the wills themselves as clearly preferable.

Once the first partner dies, the law imposes a trust on the survivor in favour of the agreed beneficiaries. The survivor can still use the property during their lifetime and can still sign a new will, but the agreed beneficiaries remain entitled to what is left when the survivor dies, and even a remarriage, which revokes the survivor's will, leaves that trust in place.

That certainty comes at a price. The consultation paper reports that practitioners would not recommend mutual wills, calling them "an inflexible device", and notes that the courts have not settled whether the trust catches property the survivor acquires after the first death. It also explains that property held under a mutual wills arrangement appears to sit outside the reach of a claim under the Inheritance (Provision for Family and Dependants) Act 1975, so a later partner or dependant may have no remedy. Mutual wills are therefore rare, and if you are considering them, advice from a solicitor is worth paying for.

What do couples use instead of mirror wills?

The usual alternative, for couples who want to protect what eventually passes to their children, is a will that leaves some or all of your estate in trust rather than outright to your partner. With a life interest trust, for example, your partner can benefit from your share during their lifetime, often by continuing to live in the home, whilst the capital is held for the people you choose and passes to them when your partner dies, which means a later remarriage or new will cannot redirect it. Our guide to wills with trusts and property protection trusts explains how these work, what trustees have to do and when they help.

Some couples combine the two approaches, keeping mirror wills for most of their estate whilst putting the home, or a share of it, into a trust. That needs careful drafting, because the way you own the property decides whether your will can reach it at all.

How does owning your home jointly affect mirror wills?

If you own your home as joint tenants, your share does not pass under your will at all. GOV.UK's guide to joint property ownership explains that a joint tenant's share passes automatically to the other owner on death and cannot be left in a will, so for many couples the most valuable asset sits outside both mirror wills until the second death. As tenants in common, by contrast, each of you owns a separate share which passes under your own will, and that is what makes it possible to leave your share to a trust or directly to your children.

Our guide to joint tenants vs tenants in common explains how to check which you have and how to change from one to the other, for which HM Land Registry charges no fee.

Do mirror wills work for unmarried couples?

Yes, and for unmarried couples a will matters even more, because without one your partner has no automatic right to inherit from you however long you have lived together. The Ministry of Justice's consultation A fairer end to relationships, published on GOV.UK in June 2026, states plainly that cohabitants currently have no automatic right to inherit when a partner dies without a will. It proposed changing that for qualifying cohabitants, but the consultation closed on 14 August 2026, the government has not yet published its response, and the law has not changed.

A partner who is left out can apply to court under section 1 of the Inheritance (Provision for Family and Dependants) Act 1975 if the two of you lived together as a couple in the same household for the two years before your death, but any award is limited to what is reasonable for their maintenance, and the government's own paper describes the process as costly and stressful. Mirror wills avoid that by making the gift directly, although gifts between unmarried partners do not qualify for the inheritance tax exemption that applies between spouses and civil partners, as Citizens Advice points out, and our guide to dying without a will sets out who else the rules leave out.

Scotland has its own succession law. Citizens Advice Scotland explains that a spouse or civil partner can claim legal rights to part of the estate even if a will leaves them little, and that a cohabitant whose partner dies without a will can ask the court for a share but must apply within six months of the death, a limit that section 78 of the Trusts and Succession (Scotland) Act 2024 extends to 12 months from 14 December 2026, so if either of you lives in Scotland it is worth asking a Scottish solicitor how mirror wills would work for you.

What happens to mirror wills if you marry or divorce?

In England and Wales, marriage or forming a civil partnership revokes an existing will under sections 18 and 18B of the Wills Act 1837, unless the will shows that you expected to marry that particular person and intended the will to survive the marriage. Couples who make mirror wills before a wedding can therefore have them written in contemplation of that marriage, whereas wills made without that wording stop working on the day you marry. The Law Commission recommended abolishing this rule in its May 2025 Modernising Wills Law report, but that is a recommendation only and the rule still applies.

Divorce works differently. Under section 18A of the same Act, once a marriage is dissolved or annulled the will stays valid but is read as if your former spouse had died on that date, so a gift to them and their appointment as executor both fall away and the estate passes to whoever the will names next. That rule only takes effect when the divorce or annulment itself is granted, and GOV.UK lists separation as well as divorce among the changes that call for a review. Our guide to changing a will covers codicils, new wills and what each of these events does.

How much do mirror wills cost?

MoneyHelper says that where your will is almost identical to your partner's, mirror wills are usually cheaper than two separate wills, although the price still depends on who prepares them and how complicated your affairs are. MoneyHelper also notes that complex cases cost considerably more and lists setting up trusts among the reasons to use a solicitor, and our guide to how much a will costs sets out the main routes and what drives the price.

The Law Society suggests using a solicitor where you share property with someone who is not your spouse or civil partner, have a dependant who cannot look after themselves, own property overseas or run a business. For straightforward mirror wills a will writer who belongs to the Society of Will Writers or the Institute of Professional Willwriters is another option, whereas mutual wills and will trusts are areas where a solicitor regulated by the SRA, or a STEP practitioner, is usually worth the extra cost.

What to do next

1. Talk through what you each want to happen on the first death and on the second, including if you were to die together.

2. Check how you own your home, because a joint tenancy passes outside both wills.

3. Decide whether leaving everything outright to each other is enough, or whether a trust, or more rarely a mutual wills agreement, suits your family better.

4. If you plan to marry, mention it when the wills are drafted so they can be made in contemplation of the marriage.

5. Review both wills every five years and after any major change, which is what GOV.UK and the Law Society both recommend.

Whatever your wills say, whoever deals with your estate will still have to find and tell every bank, utility, insurer and subscription you held, which is far quicker when you have left a clear record of your accounts alongside your wills. If that work does fall to your family, Legacy Trail's free notification service can contact the private-sector companies for them.