The Equality Act: What is Sex? The case of For Women Scotland Ltd (Appellant) v The Scottish Ministers

This blog will examine the Supreme Court’s decision in relation to the definition of sex in relation to the Equality Act 2010 in the case of For Women Scotland Ltd (Appellant) v The Scottish Ministers (Respondent) [2025] UKSC 16. The court set out its view in an 88 page judgment which is accessible via this link.

The case took a very legal approach to considering the definition of sex within the Equality Act 2010. This has led to concerns for the trans community, particularly in respect of how this judgment may impact transpeople going forwards. Due to this I think it is important to use this platform to add to the discussion of the judgment and signpost people to sources of information, especially those who may be directly affected.

At the end of this blog, I attempt to summarise some of the key points which the court set out in relation to their section within the judgment called “Why this interpretation would not be disadvantageous to or remove protection from trans people with or without a GRC” which can be found at paragraphs 248-263 of the Judgment. The Supreme Court, in doing this, has set out what could be considered discrimination, which should be helpful to inform people who may be impacted by the social ramifications of this matter on their own rights.

I should caveat this blog by saying that this is not my specialist area. This blog is intended to skim the surface of a very deep body of water so that those who read it can start to consider this case, what it appears to mean and also so people know where else they may look should they be impacted by this decision, or wish to inform themselves further. I will also signpost to paragraphs within the judgment so that those interested can go directly to them and read for themselves, should they wish to.

The issue for the Supreme Court was whether a trans person with a Gender Recognition Certificate ("GRC") could be included in their legal sex category under the protected characteristic of sex (where a trans person without a GRC would not be) and this work coherently with the Equality Act 2010. In other words, is a person with a GRC which says they are female, a “woman” for the purposes of the Equality Act 2010? This case was never intended to determine whether all trans people should be included in the protected characteristic of sex, because that has not been the case in UK law.

The Supreme Court’s conclusion was that sex, within the definition of the Equality Act 2010, refers to biological sex only, meaning that those who have a GRC are not treated as their legal sex. For example, the court took the view that a transman is legally male but biologically a female.

The court considered core provisions of the Equality Act 2010 then looked to examples of other provisions within the Act to see how they appeared to define sex. These were: separate and single-sex services; communal accommodation; single-sex higher education institutions; single characteristic associates and charities; women's fair participation in sport etc; and public sector equality duty and positive action measures for women within the armed forces (paragraphs 210 - 246 of the Judgment). The court framed its consideration in terms of comparing the treatment of transpeople with a GRC against those without, through the lens of the Equality Act 2010.

Focusing on this conflict between those who are trans with a GRC and those without and then comparing the legal reality of the permissible difference in treatment between the two led to the court deciding that the definition of sex within the Equality Act 2010 was biological sex. This means that the treatment of trans people, irrespective of having a GRC, was the same within the context of discrimination and protections under the Equity Act 2010. 

The definition of sex as prescribed by the Supreme Court opens a potential avenue by which it can become permissible to discriminate against a trans person when previously it would not have been. This is because trans people with a GRC will no longer be categorised within the sex grouping for their legal sex under the Equality Act 2010.

The Court considered this themselves, for example, at paragraph 220 of their judgment in relation to separate and single-sex services:

“The difficulty of establishing the conditions for a separate or women-only service on an approach tied to certificated sex makes it difficult to envisage any circumstances where the ability to exclude on gender reassignment grounds could operate”

The above example shows that the Court took the view that there needs to be a mechanism whereby a trans person can be excluded from separate sex-based services on gender reassignment grounds. For example, extrapolating the Court’s view, they appear to be saying that there needs to be a mechanism which could allow for a trans women to be excluded from a women’s only bathroom (or a trans man from a men’s only bathroom). 

The theme of the judgment continues with the consideration of the need to be able to discriminate against trans people in certain circumstances which could not be done in relation to those who are trans with a GRC, if that group were included in the sex category of their legal sex. The decision seems to perpetuate the binary categorisation of sex.

The Court offers a summary of their reasoning at paragraph 265 of its Judgment for those who wish to read this.

The Supreme Court seemed compelled to make this definitional change because of the real-life issues created by including trans people with a GRC into the sex category of their legal sex. However, when one steps back, this definition creates its own issues and it seems that this was not such a focus of the court when making its decision. A further concern is that although this decision was focused on trans people with a GRC, the ramifications of it will likely impact trans people as a group and not just those with a GRC. To think of a few examples, this decision may:

• Embolden those of the public, who view that someone should not be in a single sex space, to challenge that person on whether they should be in that space.
• Create the potentially absurd position that transmen could be forced to use a women’s changing room (or transwomen the men’s changing rooms) or be left without any space to change.
• Mean transpeople being placed into single sex prisons which are the opposite of their gender,  leading to a number of issues including for their safety.
• Lead to searches of a person being carried out on trans people, including strip searches, by officers of the opposite sex to them, for example male officers for trans women (and vice versa) or leave trans officers as having to conduct searches on people the opposite sex to them.

In my view, the ramifications of this decision go far beyond the above few examples, which of course the Supreme Court should be concerned with when they consider their decisions.

A way around these issues could be by not having a blanket definition of sex, but there being a more prescriptive definition of sex based on differing circumstances within the Equality Act 2010, thus altering the definition of sex appropriately for the circumstance. This would take consideration and work, but if a blanket all encompassing definition of sex is used, then on either interpretation of it, people are being harmed unnecessarily. It is my view that this work would be worthwhile. 

The court appears to have been aware of the potential harm of their decision and so, as mentioned above, spent time explaining why their interpretation would not disadvantage nor remove protection from trans people with or without a GRC.

Some key takeaways from this in relation to direct discrimination are:

• Discrimination against a trans person is discrimination because of their protected characteristic of gender reassignment.
• Direct discrimination encompasses not only cases where the complainant has the protected characteristic, but also where the discriminator perceives that the complainant has the characteristic, including where a person is treated detrimentally because it is thought that she or he has a particular protected characteristic even if they do not.
• In a case of perceived discrimination the correct comparator is someone who is not perceived to have that protected characteristic

The court uses the example that: a trans woman (a biological male with or without a GRC) can claim sex discrimination because she is perceived as a woman and can compare her treatment with that of a person not perceived to be a woman.

However, the premise of these protections, are that discrimination has taken place. What this case changed is what amounts to discrimination under the Equality Act 2010 towards trans people. This is because it changed the definition of what protected characteristic a trans person with a GRC had, there being different exceptions within the Act for what would otherwise be discrimination against those who are protected based on sex and those protected based on Gender Reassignment.

It seems now that there will be many questions which will need to be tested and adjudicated upon as well as potentially a shift of approach to place a higher onus on entities to justify their practices. It may also be that we start to see a higher amount of harassment cases under the Equality Act 2010 from the trans community as a way to shape policy and hold those to account who are interfering with their ability to live with dignity, or creating an intimidating, hostile, degrading, humiliating or offensive environment for them.

Action is being taken in relation to this case and it is my view that there will be a need, because of it, for work to be done to protect people from being impacted in their everyday lives. It seems that unfortunately this case may be being taken by institutions as redefining sex within the law generally as biological sex, rather than simply defining sex within the Equality Act 2010.

At the time of writing the Good Law project has guidance in relation to the Supreme Courts decision, for example here and is considering a challenge to this decision.