UK Supreme Court ruling: clarifying ‘Sex’ under the Equality Act 2010 and its impact on schools

A recent UK Supreme Court judgment is an important ruling which has confirmed the legal meaning of 'sex' as a protected characteristic within the Equality Act 2010.  

As with many organisations, schools are considering what this decision means for them.

We seek to explain the judgment and interim statement issued by the EHRC on 25 April 2025 and highlight the implications for schools regarding pupils and staff. This is a complex and emotive area that reminds us of the need for thoughtful policy-making and respectful cultures that support everyone.

Legal challenge to the Gender Representation on Public Boards Act 2018

The recent case of For Women Scotland v The Scottish Ministers initially arose from a challenge to the Gender Representation on Public Boards (Scotland) Act 2018 (2018 Act), which sought to define 'woman' to include transgender women. For Women Scotland Ltd (FWS), a campaign group, argued that this legal issue was a matter reserved to the UK Parliament, as it concerned statutory definitions in the Equality Act 2010.

FWS lost its case in the Outer House of the Court of Session, but the Inner House upheld the challenge. In response, the Scottish Government revised its guidance to remove the broader definition and referred to the Equality Act 2010 instead. However, the updated guidance also stated that someone with a Gender Recognition Certificate (GRC) should be treated as having changed sex, based on a provision in the Gender Recognition Act 2004 (2004 Act), which says that a person with a GRC is to be treated as their acquired gender “for all purposes”.

Supreme Court clarifies definition of 'sex' under the Equality Act 2010

FWS brought a further judicial review, arguing that transgender women with a GRC should not be included in the 2018 Act’s definition of "woman", which they argued is a reference to a biological female. This time, the Outer House rejected the claim, accepting that the 2004 Act provides a mechanism for changing a person’s legal sex, including for the purposes of the Equality Act protections based on sex. The Court found that the two Acts could work together without conflict. The Supreme Court disagreed and has found that 'sex', 'man' and 'woman' respectively are references to sex based on biology and not certification, giving its reasons which included:

• The Equality Act 2010 was based on the Sex Discrimination Act 1975 and when that legislation was passed, Parliament intended the definitions of “man” and “woman” to refer to biological sex
• The protected characteristic of gender reassignment provides dedicated protections for transgender people
• The provision in the 2004 Act which allows someone with a GRC to be treated as their acquired gender does not apply where this would make another piece of legislation unworkable or internally inconsistent and:
  • • Any such interpretation of sex within the Equality Act 2010 would render its provisions, such as those relating to pregnancy and maternity, unworkable.
    • A certified sex interpretation would have the consequence of giving trans people with a GRC greater rights than those without.
    • Certified rather than biological sex would create practical issues for organisations and undermine protections for others based on other protected characteristics including sexual orientation.

Implications for schools and organisations on single-sex provisions and trans rights

The Supreme Court’s decision provides clarity that references to 'sex' under the Equality Act 2010 always mean biological sex. This decision directly concerns trans people who hold a GRC and was in the context of service provision. The wider implications are not yet clear.  The judgment has amplified the public discourse about how the protections given in the Equality Act 2010 should be resolved where they come into conflict with one other. As was explicitly stated in the Supreme Court's judgment, the protected characteristic of gender reassignment continues to offer protections against discrimination, harassment, and victimisation for trans people and all organisations must seek to ensure that the rights of all are respected and appropriately balanced. Consequently, practical questions remain about how organisations manage potential issues, particularly regarding single-sex facilities, such as toilets and changing rooms.

EHRC guidance: interim update on how the Supreme Court ruling affects Equality Practices

The Equality and Human Rights Commission (EHRC) has confirmed it will issue a revised Code of Practice and updated guidance by the end of June to reflect the Supreme Court’s judgment. This will follow a two-week consultation in May to consider the judgment's practical implications.

To support organisations in the meantime, the EHRC has published an interim update to highlight the main consequences of the judgment. In respect of workplaces and staff, this states:

• It is compulsory to provide sufficient single-sex toilets, and where available, changing rooms.
• Trans women (biological men) should not be permitted to use women’s facilities and trans men (biological women) should not be permitted to use men's facilities. If they do so, this will mean the facilities will no longer be "single sex" and must be open to users of the opposite sex.
• Trans people should not be put in a position where there are no facilities for them to use.
• Where possible, mixed-sex facilities should be provided in addition to single-sex facilities.

In respect of pupils, it says

• Schools in England and Wales must provide separate single-sex toilets for boys and girls over the age of 8.
• It is also compulsory for them to provide single-sex changing facilities for boys and girls over the age of 11.
• Pupils who identify as trans girls (biological boys) should not be permitted to use the girls’ toilet or changing facilities, and pupils who identify as trans boys (biological girls) should not be permitted to use the boys’ toilet or changing facilities. Suitable alternative provisions may be required. 

How the judgment affects employment practices and facilities for trans employees

Since the EHRC’s update is still at an interim stage and the final guidance may provide more detail, or indeed take a more nuanced approach following consultation, schools as employers may prefer to wait for that to be published before taking substantive action. Schools must navigate this area thoughtfully, recognising the potential for strongly held and differing views within the workforce and wider school community. The interim guidance does not diminish the need to maintain a respectful and inclusive working environment where all employees' rights are upheld under the Equality Act.

Legal obligations and best practices for schools regarding trans pupils and single-sex facilities

As pupils are generally below 18 years of age and will not be eligible for a GRC, legal and regulatory requirements for pupils relating to 'sex' in schools should be interpreted based on biological sex and this has not changed.

Draft DfE Gender Questioning Children guidance published for consultation in December 2023 (under the previous government) was widely criticised for a lack of detail and nuance and we are still awaiting the final guidance.  While we cannot be certain about the detail of the final guidance, the Cass review has given important context to this issue, which we expect to inform the final guidance, and we consider that the following principles accurately reflect the legal position for schools:

• Schools and colleges have statutory duties to safeguard and promote the welfare of all children.
• Schools and colleges should be respectful and tolerant places where bullying is never tolerated.
• Parents should not generally be excluded from decisions taken by a school or college relating to requests for a child to ‘socially transition'.
• Schools and colleges have specific legal duties that are framed by a child’s biological sex.

In respect of sex-separated spaces and activities, we consider that it also remains the case that:

• Schools must make sure competitive sport is fair and safe for all pupils, which will often mean separate competitive sports for boys and girls.
• Schools must provide sex-separated toilet facilities for pupils aged eight and over and suitable sex-separated changing accommodation and showers for pupils aged 11 and over.
• Single-sex schools can refuse to admit pupils of the opposite biological sex, regardless of whether they are questioning their gender. They cannot refuse to admit pupils of the same gender because the pupil has a trans identity.
• Sleeping arrangements like dormitories, tents and shared rooms must be sex-separated.

Suitable arrangements must be made for trans pupils. This requires consideration of individual needs, but schools may consider whether a single-use facility is appropriate.

As concerns wider considerations around gender expression, pronouns, and health, these remain complex issues for schools and a considered case by case approach is recommended, to ensure that the best interests of the trans person are understood and appropriately balanced with other members of the school community in line with the principles set out above. 

We recommend that schools take legal advice concerning any changes in policy or arrangements for trans employees or pupils while the full implications of the judgment are being worked through and while the risk of legal challenge remains high.

Your school must review its policies in light of this ruling and seek legal advice to ensure all individuals' compliance and balance of rights. If you would like any assistance with this or for any further questions, please contact James Garside in our Regulatory Compliance team on 0117 314 5639, or complete the form below.