Mirror wills: what they are and when they go wrong

Mirror wills are the most common arrangement for couples: two near-identical wills leaving everything to each other, then to the children. They work well — with one important caveat.

Written by The KeepTheLot editorial team Last updated 3 min read

The short answer

  • Mirror wills are two separate, near-identical wills — usually leaving everything to each other, then to the children.
  • They cost about £250–£600 for the pair, less than two individual wills.
  • They are not binding. After the first death, the survivor can rewrite their will and leave everything elsewhere.
  • If that risk matters — second marriages, children from previous relationships — a life interest trust is the answer, not a mirror will.
  • Mirror wills also do nothing to protect a share of the home from care fees. That needs a property protection trust.
What's on this page

What a mirror will actually is#

Two wills, one for each partner, containing matching terms. The classic structure:

  • Everything to my husband/wife/civil partner if they survive me;
  • If they do not, everything split equally between our children;
  • Same executors, same guardians for young children.

They are still two independent legal documents. "Mirror" describes the content, not any legal link between them.

  • Cheaper together than separately — £250–£600 for the pair.
  • Simple and easy to understand.
  • Inheritance-tax efficient for married couples: everything to a spouse is exempt, and unused allowances transfer to the survivor, giving up to £1,000,000 on the second death.
  • One conversation covers both partners.

The weakness nobody mentions at the point of sale#

The survivor can change their will

Mirror wills are not mutually binding. Once the first partner dies, the survivor inherits everything outright and can do whatever they like with it — including making a new will that leaves your share to a new partner, one child rather than all of them, or someone you never met. Nothing in the mirror will prevents it.

This matters enormously if:

  • Either of you has children from a previous relationship. The classic outcome: the survivor remarries, their new marriage revokes their will, and on their death the intestacy rules hand everything to the new spouse — leaving the first partner's children with nothing.
  • You want to guarantee the children eventually receive a specific share.
  • There is any friction in the family about who ends up with the house.

"Mutual wills" are not the fix#

Mutual wills — a binding agreement not to change — do technically exist, but they are inflexible, hard to prove, generate litigation, and can trap a survivor whose circumstances change entirely. Most solicitors steer well clear.

The fix that actually works: a life interest trust#

Each partner leaves their share of the estate (typically their half of the home) into a trust rather than to the survivor outright. The survivor has the right to live in the property and, where the trust allows, to receive income for life. When they die, the underlying share passes to the beneficiaries you chose — not to whoever they chose later.

The same structure does double duty for care fees, because the trust share is not counted in the survivor's means test. Wills with a trust typically cost £500–£2,000. See how a property protection trust works.

When mirror wills are genuinely the right choice#

They are perfectly good if all of this is true:

  • You are in a first marriage with children only from that relationship;
  • You both genuinely trust the survivor to do the right thing;
  • Your estate is inside the inheritance tax allowances;
  • Care-fee protection is not a concern, or you have decided against it.

Practical points#

  • Sign separately. Two documents, each with its own witnesses. Do not sign each other's — it happens, and it invalidates both.
  • Review after any change — a birth, a death, a remarriage, a property purchase.
  • Marriage revokes a will. If either of you remarries, the mirror will is gone automatically.
  • Unmarried couples can have mirror wills too, and arguably need them more — with no will, an unmarried partner inherits nothing at all under the intestacy rules. What they do not get is the spousal exemption or the transferable allowances.

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Frequently asked questions

Can my partner change their mirror will after I die?

Yes. Unless the wills contain a trust or are formally constituted as mutual wills, the survivor inherits outright and can leave the whole estate to anyone. If it matters that your children eventually inherit, a life interest trust is the mechanism that guarantees it.

Do mirror wills save inheritance tax?

For married couples and civil partners they are tax-efficient rather than tax-saving: everything left to a spouse is exempt, and unused allowances transfer to the survivor, so the estate can claim up to £1,000,000 on the second death. Unmarried couples get neither the exemption nor the transfer.

How much do mirror wills cost?

Typically £250–£600 for the pair from a solicitor or regulated will-writer, versus £150–£400 for a single will. Adding a property protection trust usually brings the total to £500–£2,000.

Can unmarried couples make mirror wills?

Yes, and they should. Without a will an unmarried partner inherits nothing under intestacy no matter how long you have been together. Mirror wills fix that — though the tax position remains less favourable than for married couples.

This is general information, not legal advice. Everyone's situation is different — speak to a qualified adviser before acting. KeepTheLot is an independent information service covering England & Wales. We are not a law firm.

Written by The KeepTheLot editorial team Last updated Next review due February 2027

Part of our guide to wills.