UK Supreme Court Rules ‘Woman’ Means Biological Female Under Equality Act

The UK Supreme Court has concluded that the legal understanding of the word “woman” under the Equality Act is tied to biological sex.

This ruling follows a prolonged legal case between the Scottish government and the advocacy group For Women Scotland (FWS), which contested the inclusion of trans women with Gender Recognition Certificates (GRCs) in legislation that mandates equal female representation on public boards.

The For Women Scotland directors celebrate at the Supreme Court as others fear for trans rights in the UK. (HENRY NICHOLLS/AFP via Getty Images)

FWS argued that counting trans women as “women” under the Equality Act 2010 misinterprets the law. The Supreme Court, siding with FWS, unanimously ruled on April 16 that the terms “woman” and “sex” within the Act should be interpreted to refer specifically to biological sex.

In their detailed judgment, the justices stated that the Equality Act considers sex as a binary category—someone is either a man or a woman based on biological characteristics. Although the word “biological” isn’t explicitly used, they argued that the common understanding of the law implies biological sex.

The court explained that including individuals who have changed their legal gender via a GRC in the category of “women” would cause legal inconsistency within the framework of sex-based protections.

However, the ruling clarified that transgender people remain protected under the law through the characteristic of gender reassignment. A trans woman who faces discrimination for being transgender, or for being perceived as a woman, may still bring legal claims under existing protections.

While supporters of the ruling praised it as a victory, trans rights activists expressed concern, saying the decision represents exclusion rather than justice.