Back to Blogs

Mutual Wills the Power and Pitfalls – Inheritance plans that go wrong

By admin
14 Sep 2023

Introduction to Mutual Wills:

Mutual wills, often overshadowed by their more common counterpart, mirror wills, offer a unique and potent tool within the realm of probate law. These legally binding agreements between testators, typically spouses or partners, provide an added layer of assurance for estate distribution. In this article, we delve into the concept of mutual wills, exploring their significance, recent legal developments, and the challenges they pose in the world of probate law.

Understanding Mutual Wills:

Mutual wills take the concept of mirror wills one step further. In mirror wills, spouses or partners agree on identical terms for their wills. However, they go beyond this by incorporating a binding agreement not to alter or revoke either will after the first testator’s death. This contractual aspect is vital, as it ensures the terms of the wills remain unaltered. Clear and unequivocal evidence of this mutual intention is essential, as a mere understanding or expectation is insufficient. While creating a single joint will is an option, it is not mandatory, and an express clause in each respective will can serve the same purpose.

Legal Precedent: McLean v McLean [2023] EWHC 1863

Recent legal developments have highlighted the importance of mutual wills. In the case of McLean v McLean, the High Court grappled with the central issue of mutual wills. In this case, Reginald and Maureen McLean executed mirror wills in 2017, leaving their estates to each other and subsequently to their children in equal shares. However, after Reginald’s death in 2019, Maureen created a new will that excluded the children from Reginald’s first marriage.

While drafting the 2017 wills, Maureen and Reginald expressed trust in each other and their intent to provide for all four children. However, the court ruled against mutual wills, emphasising that a legally binding agreement had not been established. Instead, the court viewed their commitment as a moral obligation rather than a legal one. The court also explored the possibility of estoppel claims, ultimately dismissing them due to the absence of a legally binding agreement.

Key Takeaways:

Certainty vs. Flexibility: Mutual wills offer certainty in estate distribution but come with limited flexibility. Testators should carefully consider their family and financial circumstances before opting for mutual wills.

Professional Drafting: It is highly advisable to seek professional assistance when drafting mutual wills to ensure legal clarity and compliance.

Life Interest Trusts: In some cases, life interest trusts may be a more suitable alternative to mutual wills, striking a balance between certainty and flexibility.

The Complexity of Mutual Wills:

Mutual wills introduce a layer of complexity that testators and their legal advisors must navigate carefully. While they provide an ironclad assurance that the agreed-upon terms will be upheld after the first testator’s death, this certainty comes at the expense of flexibility.

One of the primary challenges of mutual wills is ensuring that the agreement is legally binding. As demonstrated in McLean v McLean, a mere expression of trust or intent to provide for certain beneficiaries may not suffice to establish the necessary legal commitment. This requirement for a clear and unequivocal mutual intention underscores the importance of seeking legal counsel when creating mutual wills.

Additionally, mutual wills may face challenges in situations where circumstances change. For instance, if a surviving spouse remarries or enters a new relationship, the inflexibility of mutual wills may become a limitation. These scenarios can lead to disputes and complications in the distribution of assets, potentially resulting in legal battles that can be emotionally and financially draining for the involved parties.

The Role of Professional Drafting:

Given the legal complexities surrounding mutual wills, it is crucial for individuals contemplating their use to seek professional guidance. Professional legal advice can help ensure that the terms of the mutual wills are carefully crafted, clearly expressing the binding nature of the agreement. Legal professionals can also provide insights into potential pitfalls and advise on alternative estate planning solutions that may better suit the testators’ needs.

Life Interest Trusts as an Alternative:

While mutual wills provide a high degree of certainty in estate distribution, they are not suitable for everyone. Testators who value flexibility and wish to account for potential changes in circumstances may consider life interest trusts as a viable alternative.

A life interest trust allows a testator to provide for a surviving spouse or partner while retaining control over the ultimate distribution of assets to beneficiaries. This arrangement strikes a balance between certainty and adaptability, as it allows for adjustments in response to changing family dynamics.


Mutual wills represent a powerful tool for couples seeking assurance in estate distribution. However, they require careful consideration and professional guidance to ensure they meet the legal standards. Recent legal cases, such as McLean v McLean, emphasise the importance of establishing a legally binding agreement in the creation of mutual wills. While mutual wills offer a unique solution, their inflexibility may not suit all circumstances.

As such, individuals should weigh the pros and cons carefully and seek legal advice when necessary to make informed decisions regarding their estate planning. Ultimately, the choice between mutual wills and alternative estate planning methods should align with the testators’ objectives, taking into account their unique family and financial situations. By navigating these complexities with professional guidance, individuals can achieve the desired peace of mind in securing their estate’s future.

Are you seeking a comprehensive review of your existing Inheritance Tax (IHT) liability and a discussion on estate planning? If so, we invite you to schedule an appointment for one of our dedicated IHT consultation sessions.

IHT Consultation

Our bespoke estate planning reports are meticulously designed to unveil your current Inheritance Tax exposure. Our reports not only shed light on potential liabilities but also offer personalised pathways to mitigate them effectively.

Key IHT Considerations:

Maximising Benefits for Married Couples
Exploring Tenants in Common Arrangements
Securing a Child’s Future with Pension Boosts
Weighing Options: Limited Company vs. Personal Property Purchase
Ensuring a Smooth Transition of the Family Home
Navigating Wedding and Annual Gift Allowances

Book an Initial Consultation Now

Book an initial consultation now with either Anton Lane or Cate Jackson, both experienced authorities in the field. This session, combined with a follow-up email, is priced at £500 + VAT.

Don’t forget to keep an eye on our socials social pages Facebook Instagram and LinkedIn

Back to Blogs

Get our latest tax articles direct to your inbox

Edge Newsletter

What best describes you?