Elouisa Crichton

The lines by which we are categorising people for the purpose of the Equality Act have not just been firmed up but have essentially changed when compared to the existing guidance and how organisations operated. Looking at the term “woman” we now know that legally this means grouping non-trans women, and trans men, together: those who are female on their birth certificate. Non-trans men and trans women are categorised as “men”, are all male on their birth certificates and are grouped together.

Let’s explore what this means in practice.

What the court decided

In For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 16, the Supreme Court ruled that:

• The terms “woman,” “man,” and “sex” in the Equality Act refer to biological sex at birth (the sex as per the birth certificate).
• This definition applies regardless of whether a person holds a Gender Recognition Certificate (GRC).
• The ruling applies across England, Scotland and Wales, as the Equality Act covers these nations.

While the case stemmed from the question of whether trans women with GRCs should count toward female representation targets on public boards, its implications extend much further into everyday situations. This interpretation takes effect now: legally it is a clarification of what was always the case but was previously understood differently by many.

Impact on equal pay claims

The ruling has specific implications for equal pay claims:

• Equal pay claims have special rules requiring comparison with someone of the opposite sex.
• Under the new interpretation, a trans woman would need to compare herself to a woman (not a man) for equal pay purposes.
• Alternative routes may be available, such as direct discrimination claims based on perception, though these are different types of claims with different legal tests.

Protections for trans people remain

The court took care to emphasise that trans people continue to have significant legal protections:

• Gender reassignment protection: All trans people remain protected against discrimination on the basis of gender reassignment. There is no suggestion that the ruling would limit the use of preferred pronouns.
• Perception-based protection: If a trans person is discriminated against because they are perceived to be a particular sex, they can still claim sex discrimination based on their acquired gender. Many aspects of the Equality Act do not require a person to legally be a particular sex in order for them to be protected. So careful reading of the law is required to understand which parts have been affected by this ruling and which have not.

The broader legal landscape

It’s important to recognise that while the Supreme Court’s ruling provides clarity on the Equality Act’s interpretation, it exists within a complex legal framework:

• Health and safety legislation: Workplace regulations require adequate facilities for all employees, with specific requirements for male and female facilities in many cases, and the reality in the UK being that the use of designated male and female spaces is common so that is the framework we are starting from.
• Facility design matters: Simply changing signage to “gender neutral” is insufficient—health and safety regulations often require specific configurations for gender-neutral facilities, such as a room that locks from the inside/sinks inside the room.
• Employee wellbeing: Obligations to staff extend to psychological wellbeing, with employers having a duty of care to all employees, some of whom may feel particularly vulnerable following this ruling.
• Potential for further developments: This may not be the final word, as there could be further cases, legislative updates, and we expect further guidance.
• Equality and Human Rights Commission (EHRC) has announced it will update its guidance to reflect the Supreme Court’s ruling. It has been clear publicly that it expects organisations to comply with the ruling and that it has enforcement powers.

Single-sex spaces: a balanced approach

The judgment has implications for how single-sex spaces operate. Finding respectful and appropriate solutions to comply with the judgment remains essential:

• Previous practice questioned: The ruling challenges the previous common practice of allowing people to use facilities matching their acquired gender regardless of GRC status. This was never set out in the Equality Act but was the common practice reflected in guidance and most policies.
• Legal position clarified: Single-sex spaces under the Equality Act must now be organised according to biological sex at birth.
• Proportionality remains key: There are limits on when these single / same sex provision can be used so at the outset there is a need to be proportionate. This could include looking again in each case on whether a single sex route is still appropriate given our changed understanding of what that means in practice (i.e. grouping women and trans men, rather than women and trans women, as a starting point). There are many scenarios where single sex spaces will still be appropriate ranging from toilets/changing facilities, to crisis support for women.
• Exceptions can still be used: Once it has been established that a single / same sex space is appropriate, the Equality Act allows for exclusion of trans people from such spaces, again where this is proportionate (and regardless of whether the person holds a GRC). Prior to this ruling we would have understood this to mean an exclusion of a trans women from a female space; but now, this exclusion would be of a trans male from a female space (and vice versa).
• Risk of “outing”: Requiring trans people to use facilities matching their birth sex (or even to move to a gender neutral facility) could effectively “out” them, creating privacy concerns and potential distress. When it comes to trans history, some individuals are openly trans, and other live by their acquired sex with their birth sex being known only to themselves and potentially a small number of people in the HR department for example. Any change in practice to use a facility of the opposite sex or a neutral facility risks “outing” these individuals.

Different organisations have different capabilities and constraints. Smaller organisations may already have only single-occupancy, non-gendered facilities, in which case no changes may be needed because facilities are not split on the basis of sex. Others may currently only have male, female and potentially separate accessible spaces. They will need to consider how to provide appropriate facilities for all users while complying with the ruling. They may find that they are limited in terms of space and resources and will need to think carefully about what solutions are possible and required. Large organisations often have more options, potentially including a mix of male, female, accessible, and gender-neutral facilities

Greater choice in facilities helps provide proportionate solutions. When gender-neutral or private spaces are used by many people, this minimises the risk of their use being conspicuous or inadvertently “outing” trans individuals.

While the ruling applies immediately, it may be that businesses take some time to make practical changes and are likely to be awaiting further guidance to be issued.

Five practical next steps

Organisations now face the challenge of implementing policies that comply with the law while respecting everyone’s dignity. Consider:

1. Engaging with affected groups to understand concerns and find workable solutions and communicate the continued commitment to respect and support for everyone.  This includes reminding everyone of existing protections against harassment and discrimination and explaining to people what the ruling has said and any practical changes.
2. Be mindful of privacy. This means not making inappropriate inquires. There can be significant legal consequences for disclosing gender recognition certificate status. Information about trans status must be handled sensitively.
3. Look carefully at your current set up and the relevant health and safety provisions. It is key to understand what facilities you have, and what is required before looking at possible changes. Where feasible, providing a mix of facilities would be helpful, including gender-neutral options alongside single-sex spaces. Care needs to be taken to ensure that accessible facilities are still available and sufficient for those who need them keeping in mind that disabled employees may need more time or to use facilities without delay.
4. Record the considerations that inform your approach. This can help to explain why an approach was taken and viewed as proportionate (for example why a single sex space is appropriate and whether any lawful exceptions have been applied regarding the use of those facilities by trans individuals). This will help to make informed choices and could act as important justification for any action you take which may impact on a person’s rights.
5. Take legal advice on your specific situation given the number of interrelated considerations and the significance of your response.

Conclusion

The Supreme Court’s ruling provides legal clarity on the definition of sex in the Equality Act. Implementing this requires careful consideration of everyone’s rights and needs.
The path forward involves ensuring legal compliance while acting with compassion – recognising that behind legal definitions are people whose experiences and needs matter equally. Listen, engage, and approach these challenges with respect and consideration for all involved.

Elouisa Crichton is a partner at Dentons