Key takeaways
Supreme Court confirms sex means birth sex
‘Man’ and ‘woman’ are defined by biological sex in law
Gender recognition certificates don’t change legal sex
Trans people remain protected, but definitions stay fixed
Ruling affects services, data and workplace policies
Organisations should review how sex-based rules apply
In an important decision for our understanding of the scope of the Equality Act 2010 and its exceptions, the Supreme Court has today unanimously held:
The terms ‘man’, ‘woman’ and ‘sex’ in the Equality Act 2010 refer to biological sex
A gender recognition certificate does not change a person’s ‘sex’ for the purposes of equality law
Legal background
The Equality Act 2010 defines the protected characteristic of ‘sex’ as meaning either a man or a woman, and these phrases are in turn defined as being a male/female of any age.
Adults with gender dysphoria, who meet minimum criteria, can make an application for a gender recognition certificate which reassigns their gender. The Gender Recognition Act 2004 establishes that trans people with a gender recognition certificate are to be considered their ‘acquired’ gender for all purposes.
This raised the question, does someone with a GRC become a ‘man’ or ‘woman’ for the purposes of the Equality Act 2010, or is the definition of ‘sex’ limited to a person’s biological sex? That question has been the subject of a long-running dispute in the Scottish courts which has now found its way to the Supreme Court.
Factual background
The Supreme Court was considering an appeal in a judicial review challenge brought by a Scottish campaign group, For Women Scotland. They were challenging the legality of guidance issued by the Scottish government regarding legislation designed to redress gender imbalances on Scottish public sector boards.
The issue to be determined by the Supreme Court was one of statutory interpretation, namely what was the meaning of the terms ‘man’, ‘woman’ and ‘sex’ in the Equality Act 2010.
Supreme Court held
In a unanimous decision, the Supreme Court has today upheld a biological interpretation of the Equality Act 2010 and held:
The terms ‘man’, ‘woman’ and ‘sex’ in the Equality Act 2010 refer to biological sex
A gender recognition certificate does not change a person’s ‘sex’ for the purposes of equality law
In summary, the Court’s rationale for its decision was:
The discrimination legislation which pre-dated the Equality Act 2010 referred to biological sex when it defined the words ‘man’, ‘women’ and ‘sex’ and these definitions were not amended by the Gender Recognition Act 2004
The rule in the Gender Recognition Act 2004, which establishes that trans people with a gender recognition certificate are to be considered their acquired gender for all purposes, is disapplied where the words of legislation (enacted before or after the commencement of the Gender Recognition Act 2004) are on careful consideration, interpreted in their context and having regard to their purpose, inconsistent with that rule
When the Equality Act 2010, which was an amending and consolidating statute, was enacted it carried across the biological meaning of the terms ‘man’ and ‘woman’ and ‘sex’ from the earlier discrimination legislation
The Equality Act 2010’s provisions relating to sex discrimination, and especially those relating to pregnancy and maternity (both risks specifically affecting women), can only be interpreted as referring to biological sex
Interpreting ‘sex’ to mean the sex certified by a gender recognition certificate would cut across the definitions of ‘man’ and ‘woman’ and this would in turn lead to numerous legal and practical problems in the application of the Equality Act 2010 and its exemptions
The correct interpretation of the Equality Act 2010 (the biological sex reading) does not cause disadvantage to trans people, with or without a gender recognition certificate because they can still invoke the Act’s protections in other ways
Practical implications
The Supreme Court decision will have very significant and obvious implications for the interpretation of the Equality Act 2010. It will have a practical impact on numerous day-to-day issues in the workplace and across wider society, such as the provision of single sex facilities and services, data collection, and single sex sports. We recommend taking specific advice, tailored to your individual circumstances, if you are concerned about these issues.
For Women Scotland Ltd -v- The Scottish Ministers [2025] UKSC 16
