Skip to main content

Insight article

June 29, 2023

Step-families and succession planning

With increasing rates of re-marriage and the resulting blended families, parents need to take action if they wish to protect children from a previous relationship's inheritance.

step image to represent step families

Photo by Liane Metzler on Unsplash

Any fans of the mega-hit TV series Succession, which follows the fortunes of the Roy siblings, will know how fraught inheritance issues can be when no clear inheritance plan is in place, especially when multiple spouses and step-families are involved. But it’s a story that’s not restricted to the super-rich like the Roys, as rising re-marriage numbers are creating more blended families and leading to inheritance disputes. 

In one recent case to reach the High Court, three siblings were cut out of their inheritance when their step-mother changed her will in favour of their step-brother after their father died. 

In 2017, the McLean couple made ‘mirror wills’, where each reflects the other, so the outcome should be the same no matter who dies first. Those wills shared the couple’s estate equally between four children, three from Mr McLean’s first marriage and the younger son born during their marriage. When the older siblings found themselves cut out of the later will, they went to court, claiming that their father had trusted his second wife “implicitly” over the terms of the inheritance.

The court has to decide whether the doctrine of mutual wills applied to their step-mother’s original 2017 will, which would mean there was an agreement between the couple to make wills with substantially the same terms and conferring reciprocal benefits and not to revoke them without the consent of the other.

“For the doctrine of mutual wills to apply, there needs to be a contract between the two testators that both wills will be irrevocable and remain unaltered, and this agreement should be incorporated into the will, or through some other form of evidence. It is not enough to make mirror wills or reciprocal wills and to show some general intention.

Without an explicit agreement not to revoke the will, any surviving partner may make a new will, with very different outcomes, and that’s why it’s important to be clear from the outset.”

Head of Private Client James McMullan

While the McLeans must wait to hear the outcome of their case, the courts have upheld another inheritance challenge in similar circumstances.

After divorcing, the Colicci’s signed a deed that covenanted that any shares they still held in their jointly-owned company would pass to their two children when they died. Both promised to make wills to support that. But the husband had remarried and later made a new will leaving his shares to his second wife, not telling his ex-wife or children what he had done. When he died unexpectedly, his later will was challenged successfully, as the court ruled that the original deed was a binding obligation which prevented either of the parents from making other arrangements to dispose of their shares on death.

According to the latest Office for National Statistics figures, almost 30% of marriages are now second or subsequent marriages. Behind the figure is a growing complexity in family structure, with step-mothers, step-fathers, step-children and step-siblings. 

“Proper planning can help satisfy everyone, and decisions will depend on individual circumstances; this could be through mutual wills containing a clear declaration that neither side can revoke or change the agreed terms without the consent of the other. 

Another option is to create a trust within a will. This can be a simple and effective way to make sure that the surviving partner has all they need while alive, but at the same time making sure that children from an earlier relationship do not miss out. It does require specialist help to get things right, but it means you can be sure things will play out as you intend.”

Head of Private Client James McMullan

A trust can allow each partner to leave their estate, or the bulk of it, in trust for the survivor and then to their children following the survivor’s death. Trusts can allow for the use of any assets – such as a house or investment income – to support the survivor for the rest of their life, but with the assets held in trust – whether for children from an earlier marriage or a charity or anyone else – when the survivor dies. 

Plan for your succession today; call private client partner James McMullan today.

Note: This article is not legal advice; it provides information of general interest about current legal issues.

Stay in touch

Subscribe to our newsletter

Stay in touch

By completing your details and submitting this form you confirm you are happy for us to send you marketing communications and that you agree to our Website Privacy Policy and Legal Notice and to us using Mailchimp to process your data.


Sending

News/Insight

  • Transactional documents in a corporate sale: What sellers should know
    Once due diligence is complete and terms are agreed, the focus turns to negotiating the transactional documents that underpin a share or asset sale. This guide explains the purpose of the key documents involved in business acquisitions and why carefu


    Read more
  • Employer warning as immigration raids hit record high 
    Employers are being urged to review their recruitment procedures after new figures revealed that immigration enforcement raids have reached record levels across the UK.


    Read more
  • Planning for the future: What to include in a UK shareholders’ agreement
    A well-drafted agreement sets clear ground rules for how the company is run, how decisions are made, and what happens when circumstances change.


    Read more
  • Understanding Court of Protection applications in England and Wales
    When someone can no longer make decisions for themselves and has not put a Lasting Power of Attorney in place, the Court of Protection can step in. This article explains what the Court of Protection does, when an application may be needed, and what t


    Read more
  • Warranties and indemnities: Key protections in share and asset sales
    An overview of warranties and indemnities in share and asset sales, explaining key differences, common protections, liability limits and risk allocation.


    Read more

What they say...

  • Laura Kelly, February 2026
    Review of legal guidance received “I recently worked with Patrick Simpson on my settlement agreement. Patrick guided me through every stage with exceptional care and diligence. He kept the process moving efficiently, always updating me promptly

  • Prasanna Sooriakumaran, February 2026
    “Really good, especially at dealing with the company that tried to overplay their hand. I highly recommend.”

  • Sharla Munian, February 2026
    Outstanding Legal Support and a Brilliant Result “I cannot recommend RIAA Barker Gillette highly enough. My solicitor supported me throughout a very challenging property litigation matter, and thanks to her expertise, dedication, and strategic

  • Client, February 2026
    Very good service in disagreement with architect “RIAA assisted me in a conflict I had with my architect, who wanted to overcharge me. The end result was satisfactory, with invoices reasonable despite being slightly higher than expected!”

  • Sharla Munian, February 2026
    Outstanding Solicitor Who Delivered the Outcome I Hoped For “After a number of years navigating a complex financial settlement following my separation, my solicitor has been incredible from start to finish. Their professionalism, patience, and

Read more
Send this to a friend