Supreme Court Defines Sex in Equality Act

For Women Scotland Ltd v The Scottish Ministers – the ruling

On 16 April 2025, the UK Supreme Court issued a landmark decision clarifying that under the Equality Act 2010, the protected characteristic of sex refers to biological sex, not gender identity or legal sex as defined by a Gender Recognition Certificate (GRC).

The case involved a challenge by the women’s rights group For Women Scotland, which contested the Scottish Government’s guidance that included trans women with a GRC in the definition of “woman” for public board gender representation under the Gender Representation on Public Boards (Scotland) Act 2018.

The Supreme Court ruled that this interpretation was inconsistent with the Equality Act, affirming that the terms “woman” and “man” refer to biological females and males, respectively. It also reaffirmed that gender reassignment is a separate, distinct protected characteristic.

Transgender protections remain in place

The Court emphasised that transgender individuals continue to be protected under the Equality Act 2010. The gender reassignment characteristic ensures that those who are transitioning, have transitioned, or intend to transition are safeguarded from discrimination and harassment. This includes employment protections such as transition leave and fair treatment throughout the process. Additionally, there are protections against discrimination by association or perception, enabling claims of indirect discrimination under Section 19A, even for those who do not belong to a protected group but share a similar disadvantage.

However, the Court affirmed that, for the purposes of the Equality Act, the definition of sex is grounded in biological sex.

Implications for employers and organisations

This ruling has significant implications for employers, public bodies, educational institutions, and service providers. It brings legal clarity to an area that has often involved differing interpretations and practices. Key considerations include:

Clarity on definition of sex: The ruling clarifies that under the Equality Act 2010 (EqA), “sex” refers to biological sex. Employers should ensure their policies, particularly those related to single-sex facilities (e.g., toilets and changing rooms), are consistent with this interpretation. Other policies, including those related to pregnancy, maternity, gender identity, and menopause, may also require review

Occupational requirements and positive action: Employers can lawfully exclude trans people with a GRC from roles requiring a specific sex or from positive action measures supporting a particular sex, provided these exclusions meet the requirements of the Equality Act 2010

Fair treatment of trans employees: Employers must maintain protections against discrimination and harassment for all employees, including trans individuals. This includes supporting diversity and inclusion efforts and mitigating any negative impact the ruling may have on trans staff

Data collection: Organisations must ensure data collection practices distinguish between biological sex and gender identity, particularly for equality impact assessments under the Public Sector Equality Duty (PSED). This is essential to comply with the Equality Act 2010 and inform decision-making on sex-based policies

Impact on service providers and associations: The judgment clarifies that service providers, associations, and charities can lawfully exclude trans individuals, regardless of GRC status, when the Equality Act 2010 permits the provision of separate or single-sex services, facilities, or associations. The Equality and Human Rights Commission (EHRC) is revising its guidance on these provisions, particularly with regard to access to single-sex spaces and we have set out the interim guidance below

Ongoing review of EHRC guidance: The EHRC is in the process of updating its statutory code of practice and other relevant guidance. This includes issues such as single-sex services and the participation of trans women in women’s sports. The updated guidance, expected by summer 2025, will provide further clarity on issues like the use of women-only spaces.

In light of the Supreme Court’s ruling, employers, service providers, public bodies, and other organisations should carefully assess their current policies and practices to ensure they align with the updated definition of sex under the Equality Act 2010. This includes reviewing policies related to single-sex services, occupational requirements, and the treatment of trans employees. It is crucial to ensure that all decisions and practices are in compliance with the Equality Act, to not only uphold legal obligations but also foster an inclusive and respectful environment for all individuals.

Equality and Human Rights Commission: interim update

The Equality and Human Rights Commission (EHRC) has provided an update following the Supreme Court ruling, outlining what it refers to as the practical implications of the decision.

The EHRC states that the decision has implications for many organisations, including workplaces, public services, sporting bodies, schools, and associations. The key points are summarised below:

Workplaces must provide sufficient single-sex toilets and changing/washing facilities where needed

Public services are not required to provide single-sex facilities, but can do so if it is a proportionate means of achieving a legitimate aim and meets the other conditions in the Equality Act 2010. However, only providing mixed-sex facilities could be indirectly discriminatory against women

In workplaces and public services, trans women (biological men) should not be permitted to use women’s facilities, and trans men (biological women) should not use men’s facilities, as this would mean the facilities are no longer single-sex and must be open to users of the opposite sex. In some circumstances, the law allows trans women to be excluded from men’s facilities, and trans men from women’s facilities. Where possible, mixed-sex facilities should be provided alongside sufficient single-sex options. Lockable, single-use rooms (not cubicles) can be used by either men or women

Schools must provide separate single-sex toilets for children over 8 and changing facilities for children over 11. Trans pupils should not use the facilities of the opposite sex, and suitable alternatives may need to be provided

Associations with 25 or more members can limit membership to men or women and can restrict membership to people with two protected characteristics (e.g., gay men or lesbian women). Women-only or lesbian-only associations should not admit trans women (biological men), and men-only or gay men-only groups should not admit trans men (biological women).