Family life takes many different forms. But when it comes to the legal recognition and protection of these different forms, the law has yet to catch up. Sarah Trotter looks into the debates over the legal recognition and protection of cohabiting (adult) siblings in the UK, and extends an invitation to those who share experience in this domain to participate in her research project.

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We know relatively little about the experiences and situations of siblings who live together as adults in the UK or, indeed, about how many siblings do so. This matters from multiple perspectives, including in terms of understanding the composition of households and families in the UK and the many forms that family life and living together take. It also matters in terms of legal recognition and protection; and it is in relation to this that the question of cohabiting siblings has arisen most often, including through efforts to raise awareness of the lack of legal recognition and protection of cohabiting siblings and through the introduction of Private Members’ Bills on civil partnership and inheritance tax that have focused on the form that such recognition and protection might take.

From the earliest days of the passage of the Civil Partnership Bill through Parliament, questions were raised about the other forms of relationship that civil partnership might also be extended to, with attempts made to include siblings who had lived together for specified periods.

The argument underlying these efforts is that cohabiting sibling relationships involve care and commitment that warrant legal recognition and protection. Concern is also expressed about the position that cohabiting siblings are in when it comes to inheritance tax, particularly about the potential for a surviving cohabiting sibling to face a bill of the kind that a surviving spouse or civil partner would be exempt from (given inheritance tax exemptions for property passing between spouses and civil partners).

Towards legal recognition

The first wave of efforts to legally recognise and protect cohabiting siblings on this basis began with attempts to amend and then extend civil partnership. This is the form of legal relationship that was introduced via the Civil Partnership Act 2004 to enable same-sex couples to formalise their relationship in a context in which marriage was restricted to mixed-sex couples. (Since then, marriage has been opened up to same-sex couples, and more recently civil partnership has been opened up to mixed-sex couples.) From the earliest days of the passage of the Civil Partnership Bill through Parliament, questions were raised about the other forms of relationship that civil partnership might also be extended to, with attempts made to include siblings (among other family members) who had lived together for specified periods.

In addition to the efforts that have been made to extend civil partnership to recognise and protect specified categories of cohabiting siblings, another line of debate has focused more specifically on the inheritance tax question.

In the years that followed the 2004 Act, the question of the position of cohabiting siblings was highlighted further, with the Utley sisters in particular doing a great deal to raise awareness of the position of siblings who lived together – including those who had, as in their case, raised the child of one of them together. Then in 2017 Lord Lexden introduced a Private Members’ Bill “to amend the Civil Partnership Act 2004 to include sibling couples”. This provided that two siblings who were over the age of 30 and had “lived together for a continuous period of twelve years immediately prior to the date of registration” would be eligible to form a civil partnership. The Bill had its second reading in the House of Lords in July 2018, where Lord Lexden emphasised the need for “committed platonic sibling couples” to have the legal rights and support that being civil partners would bring. This was not only, he stated, for reasons relating to inheritance tax, but also for purposes of wider legal provision and support, including in relation to applications for joint council tenancies and pension rights. The ensuing debate spanned questions including of the purpose of civil partnership and whether the kind of recognition and protection that was being sought here should be pursued through it.

The inheritance tax question

In addition to the efforts that have been made to extend civil partnership to recognise and protect specified categories of cohabiting siblings, another line of debate has focused more specifically on the inheritance tax question (an aspect of the civil partnership discussion, but not its entire focus). This was at the heart of the case of the Burden sisters – two sisters who had lived together all their lives and took a case to the European Court of Human Rights about their position. They argued that the inheritance tax liability that one of them would face on the death of the other (and that would not be faced by a surviving spouse or civil partner) breached Article 14 of the European Convention on Human Rights (the prohibition of discrimination) taken in conjunction with Article 1 of Protocol No. 1 (the right to the peaceful enjoyment of one’s possessions). The Court disagreed, taking the view that their relationship could not be compared with that of a cohabiting married couple or civil partners as it was “qualitatively of a different nature”. While “[t]he very essence of the connection between siblings is consanguinity”, it stated, “one of the defining characteristics of a marriage or Civil Partnership Act union is that it is forbidden to close family members”. Marriage and civil partnership were, the Court emphasised, simply different, not least on account of the “legally binding agreement” and the rights and obligations that they involved.

Addressing these questions has the capacity not only to contribute to the discussions of legal recognition and protection but to further understanding of the composition of households and families in the UK, and the forms that family life and living together take more widely.

The debate continued; and some years later, in July 2022, another Private Members’ Bill was introduced by Lord Lexden, this time “to amend the Inheritance Tax Act 1984 to make transfers between siblings exempt in certain circumstances”. The siblings to which this would apply were those who were over the age of 30 and had lived together for “a continuous period of 7 years ending with the date of the transfer”. The Bill had its first reading in the House of Lords and did not make further progress; but the position of cohabiting siblings when it comes to inheritance tax has been raised again since in debate by Lord Lexden.

The experiences and situations of cohabiting siblings

Underlying the two aspects of the question of the legal recognition and protection of cohabiting siblings lies another matter too: the matter of establishing an understanding of the experiences and situations of cohabiting siblings that can then inform these discussions. That is the purpose of the research that I am currently conducting in this context. It involves such questions as: what are the experiences and situations of cohabiting siblings in the UK? What form or forms of legal recognition and/or provision do they seek (if any)? What differences and similarities are there within and across the accounts of cohabiting siblings in this sense? What about cohabiting siblings who fall outside the category of long-term cohabiting that has been the focus of the debate to date? Addressing these questions has the capacity not only to contribute to the discussions of legal recognition and protection that I have outlined here but to further understanding of the composition of households and families in the UK and the forms that family life and living together take more widely. It also has the capacity to further understanding of sibling relationships – the relationship that can be life’s longest relationship – and so too understanding of the way in which law and policy engages with siblings and their relationships to one another more broadly.

At the heart of this project on cohabiting siblings are, therefore, accounts of experiences and situations, namely of cohabiting siblings themselves and of legal practitioners with experience of advising in this context. If you are interested in being interviewed for the project in either capacity, or in writing to me about your experience, please do get in touch. You can find out more here: www.cohabitingsiblingsproject.co.uk.

All articles posted on this blog give the views of the author(s), and not the position of LSE British Politics and Policy, nor of the London School of Economics and Political Science.

Image credit: Andii Yalaskyi in Shuterstock

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