Biology in Law: Who counts as a ‘woman’?

In the case of For Women Scotland v The Scottish Ministers [2025] UKSC 16, the Supreme Court was asked to determine whether reference to a person’s ‘sex’ was to be interpreted in light of s.9 Gender Recognition Act 2004 as including those who have a Gender Recognition Certificate (‘GRC’). Specifically in this case, the Supreme Court had to decide whether a trans woman with a GRC qualified as a “woman” under the Equality Act 2010 (‘Equality Act’) (with ‘sex’ being one of the nine protected characteristics).

In 2023, the Inner House of The Court of Session held that if a trans woman obtained a GRC, she was a ‘woman’ under the Equality Act. For Women Scotland appealed on the grounds that construing ‘sex’ in such a way would lead to, among other things, the erosion of women-only spaces if an individual born male could become a woman and have an assumed right to share those spaces with those that were born female or that a pregnant trans man (transitioning from ‘female’ to ‘male’) would lose all protections against pregnancy and maternity discrimination purely because of their acquired sex.

Judgment

The Court held that the terms ‘man’, ‘woman’ and ‘sex’ (although not defined in the legislation) should be construed as meaning biological sex at birth in the context of the Equality Act, i.e. trans people with GRCs are not treated as their acquired gender under the Equality Act.

The Court emphasised that this interpretation does not deprive trans people of all legal protections, as the Equality Act specifically identifies gender reassignment as one of the nine protected characteristics.

Trans people have additional protection against discriminatory behaviour such as direct discrimination (treating someone less favourably because of a protected characteristic) and harassment (unwanted conduct related to a protected characteristic which has the purpose or effect of creating a hostile, degrading, offensive or humiliating environment for that person) by association or perception. Under the Equality Act, discrimination claims can be brought by individuals who share a disadvantage with a protected group even if they do not have that protected characteristic.

The Court also decided that giving greater rights to GRC-holders would unfairly divide the trans community between those who hold a GRC and those who do not, and create practical issues for service providers, who cannot lawfully ask if someone holds a GRC.

What does this mean for employers?

The consequence of this judgment is that, on its face and under the Equality Act, all individuals must be treated as the sex they had at birth (irrespective of whether they have a GRC).

This may cause practical problems in the workplace, for example, transgender women with a GRC will have no legal right to use women’s gyms or shared spaces with women, such as changing rooms or toilets, if challenged, even if they are exclusively perceived to be a woman by those around them.

Whilst the practical consequences of this judgment remain to be seen and litigated, in the meantime, all employers would be wise to conduct a review of the policies they currently operate from.

How Ashtons Legal can help you

If you have received notification of a claim against your business, our team would be happy to conduct an initial review of the claim form (ET1) free of charge.

Contact our employment law solicitors today

If you would like advice on any of the issues raised in this article, please do not hesitate to contact our specialist Employment Law team by using our online enquiry form or by calling 0330 191 5713.