Sex, Gender and the Law: What the Supreme Court’s Recent Ruling Means for Employers

The recent UK Supreme Court decision in For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 16 has generated significant attention, but for most employers, we would argue that its practical impact is relatively limited—at least for now.

Rather than rewriting the law, the judgment primarily provides clarification. It confirms that under the Equality Act 2010, the terms “man”, “woman”, and “sex” refer to biological sex, as assigned at birth. That said, the ruling will likely lead to further legal challenges and case law, as those on either side of the debate seek to apply this judgment in different contexts.

Employers should not rush to overhaul policies. Instead, the focus should remain on treating all employees with respect, dignity, and fairness—something the law and the Equality Act 2010 continues to support. The Equality and Human Rights Commission (EHRC) is expected to provide an updated Code of Practice to the UK Government by the end of June 2025 for ministerial approval, and more clarity will likely emerge as ongoing and future cases play out in the courts.

What Was the Case About?

The Supreme Court reviewed Scottish Government guidance that sought to include trans women with Gender Recognition Certificates (GRCs) within the legal definition of “woman” for public board representation. The Court ruled that this interpretation was incompatible with the Equality Act 2010.

Crucially, the Court confirmed that “sex” in the 2010 Act refers to biological sex. That means:

“Women” under the Act are biological females, regardless of whether a trans woman has a GRC.
“Men” refers to biological males, not including trans men, whether or not they hold a GRC.

The judgment also clarified the relationship between the Equality Act and the Gender Recognition Act 2004. Although the GRA says a person’s sex becomes their acquired gender “for all purposes” after obtaining a GRC, the GRA itself contains a provision which made it subject to the terms of any subsequent legislation. The Court confirmed therefore that the scope and applicability of GRCs are subject to exceptions—such as where applying the rule around acquired gender would be incompatible with later legislation or make that legislation incoherent, which they concluded that it did with the Equality Act.

Trans Rights and Legal Protections Remain

The Court were eager to stress that the ruling does not remove any protections for trans people. Gender reassignment remains one of the nine protected characteristics under the Equality Act. Individuals do not need a GRC to be protected from discrimination, harassment, or victimisation on that basis. Under the Equality Act 2010, the protected characteristic of gender reassignment applies where the person “is proposing to undergo, is undergoing or has undergone a process (or part of a process) for the purpose of reassigning the person’s sex by changing physiological or other attributes of sex”.

Importantly, trans people can still bring discrimination claims based on:

Gender reassignment, regardless of whether they have a GRC.
Perceived sex, if they are treated less favourably because someone believes they are of a particular biological sex.

For example, a trans woman passed over for a promotion because she is perceived to be a biological woman may bring a claim for direct sex discrimination. Similarly, if she is harassed based on that perception, she has legal recourse under both the sex and gender reassignment provisions of the Act.

The equal pay legislation requires that someone bringing an equal pay claim must compare themselves to a person of the opposite sex.

Equal Pay: Clarified, But Still Contentious

Equal pay remains an area of legal uncertainty which will likely need clarifying further. The equal pay legislation requires that someone bringing an equal pay claim must compare themselves to a person of the opposite sex. A trans woman, with or without a GRC, cannot compare herself to a biological man who earns more than her for equal pay purposes, because under this ruling, and under the Equality Act 2010, she is not legally considered a woman.

However, she may still bring a discrimination claim if her treatment was based on the perception that she was a biological woman. The Court acknowledged that some trans individuals would be unable to access equal pay protections because of their ruling on the definition of sex under the Equality Act and how the Equal Pay laws currently define comparators—a limitation it recognised as a by-product of the statutory wording, rather than a deliberate exclusion.

This is an area where further case law may soon develop.

Facilities and the Workplace

While the judgment addressed services and representation, it did not tackle workplace-specific issues like access to toilets, showers, and changing rooms—though it has prompted fresh questions.

The Equality Act (Part 5) doesn’t deal directly with these issues, but the Workplace (Health, Safety and Welfare) Regulations 1992 require separate facilities for men and women, unless unisex, single-occupancy spaces are provided. The Court did not interpret these regulations and therefore, employers should remain cautious and assess facilities policies on a case-by-case basis, particularly given the risk of discrimination.

Single-Sex Spaces and Proportionate Justification

Contrary to some media portrayals, the ruling doesn’t newly permit the exclusion of trans individuals from single-sex spaces. The Equality Act has always allowed such exclusions—if they are a proportionate means of achieving a legitimate aim.

This ruling may embolden some to apply that provision more confidently, but the underlying legal test hasn’t changed. Blanket exclusions are still risky and likely to be challenged.

Looking Ahead: Don’t Rush, But Be Ready

So, what should employers do now?

Don’t panic or overreact. The fundamentals of discrimination law remain intact. This judgment clarifies rather than rewrites the rules.
Stay respectful and inclusive. Trans individuals are still legally protected, and nothing in the ruling permits disrespectful or exclusionary treatment.
Be prepared. Be aware of what your policies currently say and consider how you want to respond to questions you may receive either by employee members of the trans community or by employees who support strict enforcement of single sex spaces in line with the Equality Act definition of sex.
Wait for full EHRC clarity. The Commission is expected to provide an updated Code of Practice later this year following public consultation. The Commission’s interim update published on the 25 April 2025 has proved controversial and appears rushed and so we would advise against making any changes off the back of this. The interim update is also not guidance and does not have statutory effect.
Expect more case law. This ruling is unlikely to be the final word. More challenges are in the pipeline, including possible human rights-based arguments at a European level.

Final Thoughts

The Supreme Court’s ruling offers legal clarification—but not finality. It aims to reconcile legal definitions rather than settle cultural and policy debates. In many respects, the practical position for employers remains the same: respect all staff, make decisions fairly, and apply policies in a way that is lawful and balanced.

This is a legally and emotionally complex area. There are no simple answers—but thoughtful, informed, and inclusive practice remains the safest and most respectful path forward.

If your organisation is grappling with how to manage competing or overlapping protected characteristics in the workplace, please don’t hesitate to get in touch — we’re here to help.