Insights

Supreme Court rules on meaning of "sex" in the Equality Act

24/04/2025

In a judgment which has been celebrated by some and received with alarm by others, the Supreme Court has given a definitive ruling on the meaning of “sex”, “man” and “woman” in the Equality Act 2010.  This question has become increasingly loaded in the public debate over trans identities and rights.   Although the Supreme Court decision provides clarity over the law, it leaves many practical issues for employers still unresolved. 

Background to the case 

The case arose from guidance issued by the Scottish Government about gender balance on public boards.   The guidance (which had already been revised following a previous challenge) referred to the Equality Act 2010, but stated that individuals with a gender recognition certificate recognising them as a woman should be treated as women for the purposes of the guidance.  A feminist campaign group challenged this aspect of the guidance as being incorrect in law. 

The Supreme Court decision 

The question for the Supreme Court boiled down to whether the term “sex” in the Equality Act (and the words “man” and “woman”) referred to “biological sex” (i.e. sex at birth) or “certificated sex” (i.e. sex as recognised under a gender recognition certificate).   

It's worth bearing in mind that only a small number of individuals have gender recognition certificates - far fewer than the number describing themselves as trans or non-binary across the population.  The Gender Recognition Act states that a gender recognition certificate changes the person's sex “for all purposes”, but that this is subject to any contrary provision in legislation.  The Supreme Court held that this does not require an explicit statement in any legislation disapplying the effect of a certificate - it's a question of interpreting legislation to assess whether it upholds or displaces the effect of a gender recognition certificate. 

Having set out the legal approach, the Supreme Court then held that, in the Equality Act, “sex” refers to biological (birth) sex - i.e. displacing the general rule that a gender recognition certificate alters the person's sex for all purposes.  The reasoning for this was, in summary: 

  • the legislation which preceded the Equality Act, the Sex Discrimination Act, used the words “man”, “woman” and “sex” with their biological meaning, and the Equality Act did not alter their meaning;  
  • those words needed to have a consistent meaning in the Equality Act in order for the Act to be coherent and workable - the meaning could not alter depending on the context;
  • the sex discrimination provisions of the Equality Act, particularly those referring to pregnancy, childbirth, maternity leave and breast-feeding, can only be interpreted, logically, as referring to biological sex; and
  • some aspects of the Act (including provision for single and separate sex services and associations) would be unworkable if they referred to certificated sex rather than biological sex.

Implications for employers 

The Court was at pains to emphasise that, in their view, this interpretation does not reduce the legal protection for trans people, who continue to be protected under the separate protected characteristic of gender reassignment and, depending on the circumstances, may also be able to bring claims based on their perceived sex, their actual or perceived sexual orientation, their association with one sex (associative discrimination) and harassment claims.   None of these potential claims would be dependent on a gender recognition certificate. 

However, the judgment does mean that a trans woman (whether or not she had a gender recognition certificate) could not bring a sex discrimination or equal pay claim comparing herself to a male comparator.   It also has significant implications for trans participation in single-sex sports, associations and services, as well as positive action aimed at women.   

The Equality and Human Rights Commission will be updating its statutory Code of Practice to reflect the judgment, expected this summer, which will be helpful to employers and service providers.  

Workplace toilets and changing facilities 

The case throws into sharp relief the issues  for employers around use of single sex changing and toilet facilities at work.  

The Equality and Human Rights Commission has published interim guidance on the practical implications of the decision, stating as follows: 

In workplaces, it is compulsory to provide sufficient single-sex toilets, as well as sufficient single-sex changing and washing facilities where these facilities are needed….

In workplaces…:

  • trans women (biological men) should not be permitted to use the women’s facilities and trans men (biological women) should not be permitted to use the men’s facilities, as this will mean that they are no longer single-sex facilities and must be open to all users of the opposite sex
  • in some circumstances the law also allows trans women (biological men) not to be permitted to use the men’s facilities, and trans men (biological woman) not to be permitted to use the women’s facilities
  • however where facilities are available to both men and women, trans people should not be put in a position where there are no facilities for them to use
  • where possible, mixed-sex toilet, washing or changing facilities in addition to sufficient single-sex facilities should be provided
  • where toilet, washing or changing facilities are in lockable rooms (not cubicles) which are intended for the use of one person at a time, they can be used by either women or men

Employers which have allowed trans staff to use the toilets appropriate to their gender identity may face claims (e.g. from female staff) if they do not follow this guidance.  However, this does not remove their responsibility to find a safe and dignified solution for trans staff.  Nor does it eliminate the risk of claims from trans staff relating to insensitive handling of workplace transition.  This needs to be handled carefully and sensitively.   Although disabled toilets are often gender-neutral and may present a solution, employers need to assess what impact this will have on disabled staff who also need to use these facilities.   Any changes to current policy will need to be communicated carefully and will require discussion with affected staff in an effort to find a mutually acceptable solution and reduce the risk of claims. 

Gender recognition certificates

The case focused on the position of individuals with gender recognition certificates.  However, employers should remember that, in most cases, it is unnecessary and inappropriate to ask for an individual's certificate (save in limited circumstances such as right to work checks) and it is a criminal offence to disclose information relating to a certificate except in limited circumstances. 

Although it concerns a rather technical point of interpretation, the Supreme Court's judgment has been the focus of intense media interest as well as concern from LGBTQ organisations. Employers should consider how best they can support staff and reaffirm their commitment to an inclusive workplace, while also ensuring that they keep under review policies and practices in light of the judgment to ensure legal compliance.   We will be providing updates and more guidance on this as the position evolves and when the EHRC statutory guidance is updated. 

 

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