Supreme Court rules ‘woman’ in context of Equality Act means biological woman

 Lord Hodge

About this case:

• Citation:
  [2025] UKSC 16
• Judgment:
  External link
• Court:
  UK Supreme Court
• Judge:
  Lord Hodge

For Women Scotland Ltd brought the challenge to the Gender Recognition on Public Boards (Scotland) Act 2018, the second such challenge following amendments to the statutory guidance to the Act in consequence of the first action by the appellant, arguing that the Scottish Ministers had acted unlawfully in including trans women as part of meeting their target for public boards to be split 50/50 in their membership between men and women.

The appeal was heard by Lord Reed, Lord Hodge, Lord Lloyd-Jones, Lady Rose, and Lady Simler. Aidan O’Neill KC and Spencer Keen appeared for the appellant and Ruth Crawford KC and Lesley Irvine for the respondent. A joint opinion was given by Lord Hodge, Lady Rose, and Lady Simler, with which the other two judges agreed.

Certificated sex

Following the decision of the Inner House of the Court of Session that the original definition of “woman” contained in the 2018 Act was unlawful, the respondent issued new statutory guidance stating that the definition of “woman” was the same as that in the EA 2010, which at section 212 defined a woman as “a female of any age”. The guidance also stated that a person with a Gender Recognition Certificate recognising their gender as female was to be considered a woman for the purposes of the 2018 Act.

In 2022, the appellant challenged the new statutory guidance, arguing that the EA 2010 definition referred solely to biological sex and did not include trans women with a GRC. The respondent’s position was that the definition included “certificated sex”, and this position was adopted by the Outer House at first instance and the Inner House on appeal.

Lady Haldane in the Outer House rejected the appellant’s argument that the Inner House’s decision in the first judicial review had authoritatively determined that “sex” in the EA 2010 was confined to biological sex only. She held that section 9(1) of the Gender Recognition Act 2004 had the effect that a GRC changed a person’s sex for all purposes, stating that the language of section 9 of the GRA 2004 “could scarcely be clearer”.

The Inner House held that the GRA 2004 was a far-reaching enactment that created a mechanism whereby a person could change their sex in the eyes of the law. The terms “sex” and “gender” were used interchangeably in the EA 2010, and the appellant’s argument that provisions of the Act would be rendered unworkable if the wider meaning of these words was adopted was rejected. The appellant thereafter appealed to the Supreme Court.

Constant and predictable

In their joint opinion, the judges began by saying of the scope of argument: “It is not the role of the court to adjudicate on the arguments in the public domain on the meaning of gender or sex, nor is it to define the meaning of the word ‘woman’ other than when it is used in the provisions of the EA 2010. It has a more limited role which does not involve making policy. The principal question which the court addresses on this appeal is the meaning of the words which Parliament has used in the EA 2010 in legislating to protect women and members of the trans community against discrimination.”

Noting that the Equality Act was enacted in the knowledge of the existence of the 2004 Act, they added: “There is no provision in the EA 2010 that expressly addresses the effect (if any) which section 9(1) of the GRA 2004 has on the definition of ‘sex’ or the words ‘woman’ or ‘man’ used in the EA 2010. The terms ‘biological sex’ and ‘certificated sex’ do not appear anywhere in the Act. However, the mere fact that the word ‘biological’ is absent from the EA 2010 definition of ‘sex’ is not by itself indicative of Parliament’s intention that a ‘certificated sex’ meaning is intended.”

Considering the principle that a term should be interpreted consistently throughout an Act, the judges said: “The concept of sex is of foundational importance in the EA 2010. The words sex and woman appear across different parts of the Act and in many sections. It would be surprising if the words sex and woman were intended to have different meanings in different sections or parts of the EA 2010, as the Inner House concluded, especially given the definitions of ‘man’ and ‘woman’ in section 212(1) of the EA 2010. Indeed, it would offend against the principle of legal certainty and the need for a meaning which is constant and predictable, especially in the context of an Act which has such practical everyday consequences for so many individuals and organisations in society.”

They continued: “The repeated references in [sections 13, 17, and 18], to a woman who has become pregnant or who is breast-feeding only make sense if sex has its biological meaning. These plain, unambiguous words can only be interpreted coherently as references to biological sex, biological females and biological males. Put another way, if the acquisition of a certificate pursuant to section 9(1) of the GRA 2004 applies to these words, so that biological women living as trans men (with a GRC in the male gender) are male, they would nonetheless be excluded from protection when pregnant notwithstanding a continued capacity to become pregnant, and duty-bearers would not be able to claim relevant exemptions in relation to their treatment.”

The judges concluded: “Nothing in this judgment is intended to discourage the appointment of trans people to public boards or to minimise the importance of addressing their under-representation on such boards. The issue here is only whether the appointment of a trans woman who has a GRC counts as the appointment of a woman and so counts towards achieving the goal set in the gender representation objective, namely that the board has 50% of non-executive members who are women. In our judgment it does not.”

For these reasons, the appeal was allowed.