UK Supreme Court Rules that "Woman" is Defined by Biological Sex - The Employment Law Implications

30 April 2025

Introduction

A recent UK Supreme Court ruling on the 16th of April 2025, namely For Women Scotland ltd (Appellant) v The Scottish Ministers (Respondent), has asserted that the definition of "woman" is rooted in biological sex. This is a decision which carries significant implications for employment law, workplace policies, and diversity initiatives. For employers, this ruling raises critical questions about how to navigate rights and obligations under the Equality Act 2010.

The Case: Gender Representation and Legal Definitions

The case arose from a challenge to the Gender Representation on Public Boards (Scotland) Act 2018, which aimed to boost female representation in senior public appointments by including transgender women within the definition of "woman."

The Supreme Court found that the Scottish government had overstepped its legislative authority by redefining a protected characteristic established under the UK-wide Equality Act 2010. The Court ruled that the word "woman," in law, refers to a person of the female biological sex not a person who identifies as a woman.

What This Means for Employment Law

This decision has wide-ranging effects for how employers approach sex-based rights, diversity policies, and anti-discrimination protections. The following are some key impacts:

1. Protected Characteristics: Clearer Boundaries

Under the Equality Act 2010, "sex" and "gender reassignment" are distinct protected characteristics. The Supreme Court ruling reinforces that employers cannot combine these in policy or practice. For example:

• A diversity target aiming to increase "women in leadership" must be based on biological sex if it relies on legal definitions tied to the Equality Act.
• Policies must not override statutory definitions.

2. Positive Action and Diversity Quotas

Many employers implement positive action initiatives to improve gender balance in recruitment and promotion. This ruling may require a review of such programmes to ensure compliance with legal definitions.

• Employers who have counted transgender women in "female representation" statistics may need to reassess how these figures are compiled and reported.
• Targets must align with legally recognised definitions to avoid claims of unlawful discrimination.

3. Single-Sex Spaces and Roles

Some roles or facilities in the workplace may lawfully be restricted to one sex, where this can be objectively justified such as for privacy, safety, or welfare reasons. The ruling strengthens the legal basis for employers to:

• Maintain single-sex toilets or changing facilities, where appropriate.
• Specify biological sex as a genuine occupational requirement in limited circumstances, such as in certain care roles or security settings.

4. Trans Rights in the Workplace

Importantly, the ruling does not remove or diminish the legal protections for transgender employees under the characteristic of "gender reassignment." Employers must continue to:

• Protect against harassment, victimisation, and discrimination based on gender reassignment.
• Support transgender staff in transitioning, including through name changes, pronoun usage, and access to inclusive policies.

Critically, employers must now draw a clearer legal distinction between sex-based rights and gender identity inclusion both of which are protected, but under different provisions.

HR and Legal Considerations: What Should Employers Do?

In light of the ruling, we, at Schofield & Associates advise that employers to take the following steps:

• Review diversity and inclusion policies to ensure that legal definitions of sex and gender are correctly applied.
• Train HR teams and managers on the distinction between protected characteristics and how to apply them in practice.
• Ensure clarity in job descriptions and hiring practices when referencing gender, especially where positive action is in place.
• Provide support for all staff, balancing rights under both the "sex" and "gender reassignment" characteristics.
• Audit gender-based targets to confirm alignment with the Equality Act's framework.

Conclusion

The UK Supreme Court's ruling offers legal clarity that will reshape how sex and gender are treated within employment law. Whilst the judgment reinforces that "woman" refers to biological sex in law, it does not negate the rights of transgender employees, rather emphasising the importance of precise legal language and compliance.

For employers, this is a moment to carefully review policy, practice, and culture ensuring that everyone's rights are respected, and that legal obligations are fully understood and implemented. At Schofield & Associates, we're here to assist you in making sure that your business and your policies are compliant with law.

If you're looking for advice, please contact:

Eileen Schofield for Employment Law advice on eileen.schofield@schofieldandassociates.co.uk - 01564 334614

Derri Moran for HR advice on derri.moran@schofieldhr.co.uk - 07508 741505

https://www.schofieldandassociates.co.uk/

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