Employment Law Digest May 2025 – The Supreme Court decides: implications for employers following the decision on the definition of a woman

The Supreme Court held that sex means biological sex at birth, meaning that a woman is a person born a biological female, and a man is a person born a biological male. This means that if a person identifies as transgender, their sex for the purposes of the Equality Act remains their sex at birth, even when they have a GRC.

The background to this case has been well reported in the media, with strong positions being taken on both sides of the debate. Previous guidance from the Scottish government stated that the definition of ‘woman’ was the same as that under the Equality Act 2010, and that it also included a person with a GRC recognising that their gender is female. This case challenged the lawfulness of this statutory guidance, which resulted in a recent Supreme Court ruling on the definition of sex for the purposes of the Equality Act 2010.

It is difficult to escape the fact that this is an emotive and divisive issue. Whatever your own personal view on the decision, it is certainly the case that this decision has potentially wide reaching implications under equality law and is an issue that employers may be required to consider.

Employers will need to balance their obligations to all staff and job applicants, and this may not always be straightforward. Irrespective of the recent Supreme Court decision, transgender people are still protected from harassment under the Equality Act 2010: this has not changed. In the same way, gender as a protected characteristic under the Equality Act 2010 also remains.

One practical consequence of the decision that is immediately clear is in relation toilet facilities, which although we now have clarification, continues to be a vexed question.
Employers now need to ensure that they have sufficient single-sex facilities for employees. Single-sex toilets, and changing rooms and washrooms (where employers have them) must be provided. These will need to be strictly maintained as single-sex in order to comply with the Workplace (Health, Safety and Welfare) Regulations 1992, and any transgender employees will be required to use the toilet of their assigned sex at birth.

The exception is where toilets, changing rooms and washrooms comprise of one single unisex cubicle which is lockable. Employers who have these can continue to use them as unisex facilities. This seems like the ideal arrangement to implement, but how feasible this is will depend heavily on the specific business premises and ability to make any changes.

We would recommend checking any policies that may be impacted by this decision. A minority of employers may have policies around use of toilets/changing rooms/washrooms, and these should be reviewed to confirm that there is nothing which allows single-sex spaces to be used by members of the opposite sex. For example, some policies may contain wording which allow for case-by-case assessment of someone of the opposite sex to use a single-sex space. Any case-by-case assessment of this type will now be unlawful and will need to be removed.

The Supreme Court decision has placed greater focus on the rights of woman and the rights of transgender people. Whilst the decision from the Supreme Court does provide some clarification on the issue, a number of questions around practical implications remain unanswered and further legislative clarification is almost certainly required. As the Supreme Court said when delivering its judgement, this should not be seen as a victory of one side of the debate over the other. The law often struggles to keep pace with society and implications that were not even contemplated decades ago have come into sharp focus. The role of the Supreme Court in reaching their decision was not to weigh in on an ideological debate: they are simply concerned with the interpretation of the legislation. The question for them was broadly what is meant by the term “woman” under the Equality Act. The simplest interpretation, the binary one, was the one arrived at in the end. The Supreme Court is not passing their own judgement on the matter: rather, they are looking at the meaning of the words, given the many pieces of legislation that refer to ‘men’ and ‘women’ it was crucial to establish a clear definition across the board.

For employers, it will be a case of watch this space for further clarification and guidance on what this decision means for them. Regardless of the outcome of this case, the Equality Act 2010 continues to provide important protection for individuals with particular protected characteristics and the Supreme Court has not changed this.

If you would like further information or guidance on this topic please contact your usual advisor or contact Gillian Chinhengo.