Supreme Court clarifies ‘sex’ definition in Equality Act 2010

Judgment brings some legal clarity but raises practical and ethical questions for employers.

The Supreme Court gave its judgment in the landmark case of For Women Scotland v The Scottish Ministers on 16 April. The judgment makes clear that the terms “sex”, “woman” and “man” in the Equality Act 2010 (EA 2010) refer to “biological sex” and not “certificated sex”. In other words, for the purposes of the EA 2010, the sex of a trans person who has obtained a Gender Recognition Certificate (GRC) will be their sex as recorded at birth.

In one sense this judgment provides clarity. It makes clear that, as the law stands, whenever the terms “man” and “woman” are used in the EA 2010, this means a biological man or woman. This applies across all relevant protections against discrimination and harassment in the EA 2010 – including duties on employers, service providers, governing bodies and proprietors of schools and education institutions, and associations with at least 25 members.

It also applies to exceptions to discrimination protections, including occupational requirements for an employee in a certain role to be a woman or a man, and to the exceptions for service providers who are justifiably providing separate and single-sex services. Importantly, organisations should be aware that they will not be able to rely on these exceptions to sex and gender-reassignment discrimination claims if trans people with a GRC have been appointed to roles with a sex-based occupational requirement or admitted to single-sex services in line with their acquired gender as set out in the GRC.

In other ways, the judgment raises more questions than answers. It does not deal with how employers should in practice determine who is biologically female or male and when they might be required to do so. Nor does it include any reference to intersex individuals who are assigned a certificated sex at birth.

Case details: For Women Scotland v The Scottish Ministers

The case was brought by For Women Scotland (FWS), an organisation campaigning to protect and strengthen women’s and children’s rights in Scotland. FWS brought judicial review proceedings against the Scottish Ministers contending that revised government guidance supporting legal requirements in Scotland for gender representation on public boards was unlawful.  The guidance stated that trans women with a GRC should be included when counting the number of women on boards. FWS argued that the definition of a woman under the EA 2010 should be taken to be a reference to a biological woman and so should not include trans women, with or without a GRC.

The Outer and Inner House of the Court of Session determined that the guidance was not unlawful on the basis that under the Gender Recognition Act 2004 (GRA 2004) a person’s sex on obtaining a GRC becomes that of their acquired gender “for all purposes” subject to exceptions in the GRA 2004 and other enactments. 

FWS appealed to the Supreme Court which overturned this decision, ruling that the guidance is unlawful as the term “woman” in the EA 2010 means a biological woman and does not include a trans woman with a GRC.

The basis for this judgment was that:

• The exception in the GRA 2004 disapplies the rule that a GRC changes gender for all purposes where the words of legislation enacted before or after the GRA 2004 are inconsistent with this rule;

• The terms man and woman in the Sex Discrimination Act meant biological man and biological woman and the EA 2010 did not amend this definition;

• It is important that the EA 2010 is interpreted in a clear and consistent way so that people who share a protected characteristic can be identified by those on whom the EA 2010 imposes obligations, so that they can perform those obligations in a practical way;

• Interpreting the term “sex” as certificated sex rather than biological sex would cut across the definitions of “man” and “woman” and the protected characteristic of sex in an incoherent way. In particular, the EA 2010 provisions relating to pregnancy and maternity and to the protection of women can only be interpreted as referring to biological sex;

• The words woman, man and sex must have the same meaning whenever they are used in the EA 2010 – they cannot refer only to biological sex in provisions relating to pregnancy and maternity, but include certificated sex in other provisions;

• If trans people with a GRC had greater rights under the EA 2010 than other trans people, organisations would be in a difficult position as they would have differing duties towards each group but would not be able to distinguish between them as they would not be able to ask people whether they had obtained a GRC;

• Provisions in the EA 2010 concerning separate sex and single-sex services require a biological interpretation of sex in order to function properly (including changing rooms, hostels and medical services); and

• Provisions in the EA 2010 relating to single-sex associations and charities, sport, the armed forces and the public sector equality duty would be incoherent and impracticable without a biological interpretation of sex.

The Supreme Court stated that interpreting sex as biological sex “does not cause disadvantage to trans people, with or without a GRC. In the light of case law interpreting the relevant provisions, they would be able to invoke the provisions on direct discrimination and harassment, and indirect discrimination [based on the protected characteristic of gender reassignment]. A certificated sex reading is not required to give them those protections.”

There is no further appeal within the UK courts in relation to this judgment. It has been reported that this decision may be subject to challenge in the European Court of Human Rights.

Equality and Human Rights Commission interim update

On 25 April, the Equality and Human Rights Commission (EHRC) published An interim update on the practical implications of the UK Supreme Court judgment. This states amongst other things that:

• 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.

• It is not compulsory for services that are open to the public to be provided on a single-sex basis or to have single-sex facilities such as toilets. These can be single-sex if it is a proportionate means of achieving a legitimate aim and they meet other conditions in the [EA 2010]. However, it could be indirect sex discrimination against women if the only provision is mixed-sex.

• In workplaces and services that are open to the public:

  • 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

This update has proved controversial, with many commentators criticising the impracticability of the guidance and the risk that it leads to public confusion, social tensions and significant distress for trans people.

The judgment and the EHRC interim update both overlook the fact that it is by no means straight-forward to determine biological sex in all circumstances, and that commonly there is no check undertaken on people entering spaces designated as single-sex.

The EHRC interim update as it relates to service providers was debated in the House of Lords on 1 May where it was clarified that the Government did not have sight of the update before it was published. Baroness Smith of Malvern (Jacqui Smith) who is a government minister for Women and Equalities, stated that “The Government have set out our expectation that service providers follow the clarity that the [Supreme Court] ruling provides. The EHRC’s interim update provides a perspective on how the judgment and Equality Act are practically applied in some areas; it is a snapshot reflection, rather than full guidance. The EHRC has announced that it will update its statutory Code of Practice and has committed to seeking views from affected stakeholders; I am sure that it will consult widely on this. I add that the application of the Supreme Court ruling to different services and settings is complex. It requires careful work to ensure that we provide clarity for a wide range of varied service providers of different kinds and sizes so that they have confidence in how they apply the Equality Act on a day-to-day basis.”

The EHRC has stated that it will hold a two-week consultation on a draft updated statutory Code of Practice in mid-May. It is expected that the updated Code will be published by the end of June.  The Chair of the Women and Equalities Committee has recently written to the Chair of the EHRC to raise a number of questions, including suggesting that the consultation period is extended to at least six weeks and that the updated Code should clarify the rights of trans people and consider submissions on legal implications beyond the Supreme Court ruling.

For many employers who have followed best practice guidance that trans colleagues should as far as possible be supported to use facilities relating to their affirmed gender (whether they have a GRC or not), the update represents a stark change in approach and has led to uncertainty about whether they are now legally required to exclude trans people from single-sex facilities. 

Legal obligations on employers to provide suitable toilets for staff

The EHRC interim update has been criticised as misleading in relation to obligations on employers when it comes to the provision of toilets for staff.

The law on the provision of toilets for employees is set out in the Workplace (Health, Safety and Welfare) Regulations 1992 (the Regulations). The Regulations state that “suitable and sufficient sanitary conveniences shall be provided at readily accessible places” and specifies further that toilets will not be suitable unless “separate rooms containing conveniences are provided for men and women except where and so far as each convenience is in a separate room the door of which is capable of being secured from inside”.

Further information for employers on requirements for staff toilet and washing facilities is available on the Health and Safety Executive website: Have the right toilets and washing facilities - HSE.

The terms men and women are not defined in the Regulations, and it is notable that the recent Supreme Court judgment has only clarified the meaning of man and woman for the purposes of the EA 2010 and not for other laws such as the Regulations. Some commentators have expressed a view however that the purpose of these provisions (providing suitable sanitary conveniences for employees) means that the terms would be interpreted in the same way as the Supreme Court has interpreted them in the EA 2010.

Next steps for employers following Supreme Court judgment

Many employers have sought to reassure employees who are concerned about the immediate implications of this judgment and the EHRC update. Employers taking this approach may wish to issue a statement to staff referring to the judgment which:

• acknowledges that views differ on this subject and that it is a sensitive issue;

• recognises that some staff may be concerned by the judgment and the debate which is ongoing around it;

• makes clear that statutory guidance from the EHRC is expected and reassures staff that there will be no immediate change in policies or practice and that staff will be consulted before any changes are made; and

• restates the organisation’s values in relation to equity, equality, diversity and inclusion and reminds colleagues of the importance of mutual respect and tolerance.

Where organisations rely on the occupational requirement exceptions of the EA 2010 to designate some roles as women-only or men-only, they should undertake a review of current employment practice and consider steps needed to ensure the exception still applies. Legal advice should be taken at an early stage, particularly where this judgment will impact on the employment of a trans colleague. 

Employers should remain alert to the provisions of the EA 2010 which protect trans colleagues from discrimination and harassment on the basis of gender reassignment. Making changes to policy and practice which lead trans colleagues being disadvantaged or reasonably to feel intimidated, offended or that their dignity is violated could lead to complaints and claims.

Similarly, employers should be aware of the risk of employee conduct in relation to this issue constituting harassment and discrimination, either on the basis of sex or gender reassignment. Employers should also bear in mind that the EA 2010 provides protection in some circumstances for those who express their beliefs, including gender critical and trans rights beliefs. For more detail on the risks of disciplinary action for expressing protected beliefs please see our article from March 2025: School employee’s dismissal due to reputational risk of Facebook posts was belief discrimination - Wrigleys Solicitors LLP.

This is a highly sensitive area where there are strong views on each side. We recommend that employers seek legal advice in this area when considering policy and practice and when managing specific incidents and issues in the workplace. Please contact Wrigleys’ employment team for assistance.

If you would like to discuss any aspect of this article further, please contact our employment team on 0113 244 6100. 

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The information in this article is necessarily of a general nature. The law stated is correct at the date (stated above) this article was first posted to our website.

Specific advice should be sought for specific situations. If you have any queries or need any legal advice please feel free to contact Wrigleys Solicitors.