The Supreme Court unanimously determined that “man,” “woman,” and “sex” in the Equality Act 2010 refer exclusively to biological sex, finding that a “certificated sex” interpretation would render numerous provisions incoherent and impracticable to operate, particularly those concerning pregnancy, single-sex spaces, sports participation, and public sector equality duties.

Background

This appeal stemmed from a challenge to statutory guidance accompanying the Gender Representation on Public Boards (Scotland) Act 2018. Following a previous successful challenge (FWS1) to the original guidance on legislative competence grounds, the Scottish Ministers issued revised guidance stating that persons with Gender Recognition Certificates (GRCs) recognising their gender as female were considered women under the Equality Act 2010. For Women Scotland, a feminist organisation, contended that “woman” under the Equality Act 2010 refers exclusively to biological sex, maintaining that a biological male with a GRC in the female gender does not fall within the statutory definition. The Scottish Ministers argued for a “certificated sex” interpretation that would include transgender women with GRCs within the definition.

Judgment

The Supreme Court unanimously allowed the appeal. Lord Hodge, Lady Rose and Lady Simler delivered a joint judgment (with Lords Reed and Lloyd-Jones concurring), holding that the terms “man,” “woman”, and “sex” in the Equality Act 2010 refer exclusively to biological sex. The Court expressly rejected the Inner House’s approach that these terms could have different meanings in different sections of the Act, insisting on consistent interpretation throughout the legislation. The Court concluded that section 9(3) of the Gender Recognition Act 2004 operates to disapply the general rule in section 9(1) that a person with a GRC should be treated as their acquired gender “for all purposes.” This disapplication occurs because the provisions of the Equality Act 2010 would be rendered incoherent by a “certificated sex” interpretation, particularly provisions relating to pregnancy and maternity, separate spaces, single-sex services, communal accommodation, sports participation, and equality duties.

Endnote

While establishing that “sex” in the Equality Act 2010 refers consistently to biological sex, the Court explicitly confirmed that transgender persons remain protected from discrimination through the protected characteristic of gender reassignment. The judgment emphasises that transgender people can invoke provisions on direct and indirect discrimination without requiring a “certificated sex” interpretation, as existing case law allows transgender persons to claim sex discrimination when they are perceived to be of a particular sex.

Read the full decision of the Supreme Court at For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 16