The Supreme Court has ruled that “sex” means “biological sex” in a landmark case looking at the definitions given in the Equality Act.
Yesterday, (16 April 2025) The UK Supreme Court ruled that the terms “man,” “woman,” and “sex” in the Equality Act 2010 must be interpreted as referring to biological sex, and not gender identity, and specifically that it cannot be changed even if a transgender person has a Gender Recognition Certificate (GRC).
The Background of the Legal Case
The background of the case is long and relatively complex – all starting from Scotland with the Gender Representation on Public Boards (Scotland) Act 2018, which aimed to increase female representation on public boards. This Act defined a “woman” to include not only biological females, but also trans women with or without a GRC. This approach was contested by an advocacy group, who argued that it would alter the UK-wide definition of “woman” as used in the Equality Act 2010, which is outside the Scottish Parliament’s devolved powers.
The case has been ongoing for over 6 years with it having gone through every appeal court before reaching the UK Supreme Court. By the time it got to the Supreme Court, the main question for the court was whether a GRC, granted under the Gender Recognition Act 2004, changes a person’s “sex” for the purposes of the Equality Act 2010, which is the legislation which protects against discrimination based on sex and, separately, gender reassignment, among other characteristics.
The court yesterday ruled that the terms “man”, “woman” or “sex” must be interpreted as referring to biological sex for the purposes of the Equality Act.
What were the practical issues?
The practical challenges being faced by some settings regarding the legality of the use of single-sex spaces, such as changing rooms and refuges, were the main thrust of the debate in the legal challenge.
Some other high-profile examples included in maternity care, sports and representation on public boards. The court ruled that allowing “sex” to include “recognised sex” or “certified sex” would cause too much difficulty for these providers in identifying which group an individual belonged to. They were also concerned about whether such an approach would create two tiers of trans rights – for example granting more protection to those with a GRC, which many trans people choose not to get. The court highlighted that those service providers would have no way to distinguish between the two trans sub-groups because they could not ask whether a GRC had been obtained – that information is private and does not need to be disclosed by the individual.
What does the ruling mean for me in practice?
The Supreme Court concluded that the Equality Act’s provisions, especially those regarding pregnancy, women-only spaces, sports, and charities, only function properly if “sex” is interpreted as biological. The decision may, therefore, change how public bodies, service providers, and campaigners understand and implement sex-based rights across the UK.
Importantly, the court went to great lengths to explain that this interpretation for this specific purpose does not remove the anti-discrimination legal protections from trans people. Trans individuals are protected and continue to be protected under the Equality Act by the protected characteristic of gender reassignment, regardless of whether or not they hold a GRC.
If you are a trans person, this means that you remain protected from direct and indirect discrimination, harassment, and can claim sex discrimination if you are treated unfairly based on perception.
Whilst the decision has been made regarding the legal definitions, it does feel like a wider debate will remain ongoing for the years to come regarding how all of these competing rights are balanced against one another and we correctly protect the rights of marginalised groups. Watch this space.
How can BTO help you?
Here at BTO, our Modern Families team are experts at the law surrounding LGBTQ+ rights, including in the area of Fertility Law & Family Creation. Beverley Addison is a well-known expert practitioner in Scotland advising all kinds of families on their legal rights and ability to create and take care of their families. She has helped many LGBTQ+ individuals, parents and families over the years, both in the area of family creation and in complex separations.
You can arrange a consultation with Beverley here Contact – BTO Solicitors Glasgow and BTO Solicitors Edinburgh or call 0141 225 5277.