Why Mutual Wills Can Be Problematic

and What to Do If You Need to Challenge a Mutual Will

By Clodes Solicitors – Contentious Will Experts Serving England and Wales

What Are Mirror Wills?

Mirror wills are two separate wills, usually made by couples, with the same or very similar terms. Each party typically leaves their estate to the other, and then to agreed beneficiaries (often children). Mirror wills are flexible: either party can revoke or change their will at any time while they are alive.

Key features:

No legal contract not to change the will.
Can be changed at any time (even after the other party’s death).
Simple, common, and usually non-contentious.

What Are Mutual Wills, and Why Are They Problematic?

Mutual wills involve two people making wills on similar terms, but with a crucial difference: they enter a legally binding agreement not to change or revoke their wills (without both parties’ consent) during their lifetimes – and for the survivor, after the first death.

Common intentions:

“Bloodline protection” in blended families (to prevent the survivor leaving everything to new partners or stepchildren).
A desire for certainty or to “lock in” an agreed inheritance pattern.

Problems with mutual wills:

Lack of flexibility: Once one party dies, the survivor is bound – even if circumstances change.
Disputes and litigation: Many couples do not understand what they have signed; beneficiaries often contest the meaning or binding force of the wills, leading to expensive legal proceedings.
Rigid and outdated: Modern family arrangements and better trust structures often provide more suitable alternatives.
Hard to change: If the survivor wishes to make a new will or their situation changes, they may be prevented by the mutual wills contract.

Can You Change a Mutual Will After One Party Has Died? What If There Is a Dispute?

No. Once the first testator has died, the survivor is legally bound by the mutual wills agreement. If a new will is made, the court can compel the executor to distribute the estate as set out in the mutual will.

If you believe you are affected by a mutual will, or wish to challenge its enforceability – for instance, if you are:

The surviving party feeling trapped by the arrangement,
A beneficiary disappointed by a new will,
Unsure whether the arrangement was truly “mutual” and binding,

Challenging a Mutual Will may be your only remedy.

Challenging a Mutual Will: How to Seek a Declaration

You or your solicitor can apply to the High Court for a declaration about the status or validity of the mutual will. Such claims often proceed under Part 8 of the Civil Procedure Rules, especially where the main issue is legal interpretation rather than contested facts.

The Court Will Consider:

Is there clear evidence of a binding agreement not to revoke or alter the wills (not just mirror wording)?
Did the parties have full knowledge and approval of the arrangement?
Was it genuinely intended to be irrevocable – with the parties understanding its effect?
Was there capacity, or was there undue influence or lack of independent legal advice?
Did the survivor act inconsistently (e.g., by making a new will, large gifts to others, etc.)?
Are statutory formalities met?
Is enforcement fair and just (public policy/fairness)?

If the court finds no binding arrangement, it may issue a declaration allowing the survivor to make a new will. If it finds the mutual will is valid and binding, it will enforce the original agreement– even over a later will.

Recent case law includes:

Naidoo v Barton [2023] EWHC 500 (Ch) – Confirmed mutual wills as contracts; allowed for challenge based on undue influence.
McLean v McLean (CA, July 2023) – The court requires strong evidence of a mutual will contract, not just expectations or informal promises.
Colicci v Grinberg [2023] EWHC 1177 (Ch) – Recognised that testamentary obligations can survive later legal arrangements.

Practical Steps for Challenging a Mutual Will

Evidence Checklist:

Copies of both wills; any letters, deeds, or agreements referring to wills as “mutual” or “irrevocable”
Solicitor’s file and notes, especially about advice on irrevocability and alternatives
Details of any independent legal advice (or its absence)
Medical and capacity evidence at the time the wills were made
Evidence of undue influence or family pressure
Property ownership documents (joint tenancy or tenants in common)
Evidence of any new wills or significant gifts after the first death

Procedural Roadmap:

Pre-action: Letter before claim; seek disclosure of relevant documents.
Issuing the claim: Usually under Part 8; may convert to Part 7 if substantial factual disputes arise.
Responding: Executors/beneficiaries may be joined; the court will consider evidence and legal argument.
Costs: Successful claimants can often recover their costs, though costs are always at the court’s discretion.

Estimated legal costs:
Uncontested declaration (Part 8): £8,000 – £15,000 plus VAT/disbursements.
Contested (Part 7/trial): £15,000 – £35,000 plus VAT or more.
Costs orders are discretionary and depend on the conduct of the parties and the merits of the challenge.

Are There Better Alternatives to Mutual Wills?

Yes. Modern estate planning offers safer, more flexible tools, including:

Life interest trusts in wills (allowing a survivor to benefit from assets for life, with capital protected for children)
Discretionary trusts
Carefully drafted declarations of trust and letters of wishes
Reviewing asset ownership (e.g. tenancies in common)

If you are considering your own wills, always seek professional advice before agreeing to any arrangement that could be considered irrevocable.

Frequently Asked Questions – Mutual Wills and Mirror Wills

Are mirror wills the same as mutual wills?
No. Mirror wills are simply wills with similar terms, and can be changed at any time. Mutual wills are based on a binding contract not to change them, and can rarely be changed after death.

Can you revoke a mutual will after your partner dies?
Generally, no. The survivor is bound by a constructive trust and the agreement will usually be enforced.

Can lifetime gifts defeat a mutual will?
Any attempt to defeat the mutual will trust by gifting away assets may be challenged and set aside if beneficiaries bring a claim.

Does joint tenancy affect mutual wills?
Joint tenancy determines how property passes on death, but does not prove or disprove a mutual will contract. The evidence of the parties’ agreement is critical.

Is independent legal advice important?
Almost always. Lack of independent legal advice can support a challenge to a mutual will on grounds of undue influence or lack of knowledge and approval.

Why Instruct Clodes Solicitors?

At Clodes Solicitors, our contentious will experts act for clients across England and Wales in all types of will challenges, including mutual wills, mirror wills, undue influence, capacity, and Inheritance Act claims. We have extensive experience obtaining declaratory relief from the High Court and resolving complex estate disputes.

We can assist with challenging mutual wills or defending a mutual wills claim.
We offer clear, practical advice, fixed-fee initial consultations, and a costs-managed strategy.
We accept instructions from clients nationwide and can advise on all forms of will challenges and contentious probate.

Contact Clodes Solicitors today on 02920 765050 or at reception@clodes-solicitors.com for expert advice if you are considering challenging a mutual will, need to obtain a court declaration, or want to protect your rights in any contentious probate dispute.

This article applies to England and Wales. It is for general information purposes only and does not constitute formal legal advice. Costs and legal outcomes depend on individual facts and are subject to court discretion. For tailored guidance, please contact Clodes Solicitors directly.