9 Things to Know About UK Supreme Court Ruling on Sex, Gender9 Things to Know About UK Supreme Court Ruling on Sex, Gender
Protesters gather outside the Supreme Court in London on Nov. 15, 2023. On April 15, the UK's highest court ruled that the words "woman" and "sex" refer to "a biological woman and biological sex" in a landmark case. Leon Neal/Getty Images

9 Things to Know About UK Supreme Court Ruling on Sex, Gender

The UK’s highest court has put into question the use of ‘gender recognition certificates,’ which legally recognize a person’s chosen gender identity.
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In a landmark decision that follows years of confusion, anger, and campaigning, the UK’s highest court has ruled that the words “woman” and “sex” refer to “a biological woman and biological sex.”

The case sought to clarify the question of whether a person who holds an official certificate recognizing that individual’s gender as female is entitled to women’s rights protections under the law.

A commonly cited example was the question of whether women-only services—such as rape crisis support groups—were allowed to exclude men with gender recognition certificates.

A gender recognition certificate indicates that a person’s chosen gender identity is legally recognized.

Obtaining the certificate requires a medical diagnosis of gender dysphoria, having lived as the identified gender for at least two years, and the intention to live as that self-identified gender until death.

More than 8,000 gender recognition certificates have been granted in the UK since their introduction under the Gender Recognition Act of 2005.

1. How Case Was Sparked

The case was instigated by campaign group For Women Scotland in 2022, which brought a series of legal challenges, beginning in Scotland and culminating in the UK Supreme Court, over the definition of the word “woman” in the Gender Representation on Public Boards (Scotland) Act of 2018.

This legislation was passed by the Scottish Parliament and mandated that 50 percent of individuals on public boards be female. Its definition of “female” included males who identify as women.

For Women Scotland’s lawyers argued that not tying the definition of sex to its “ordinary meaning” could have far-reaching consequences for sex-based rights, as well as for “everyday single-sex services” such as bathrooms, changing rooms, hospital wards, and domestic violence and rape crisis centers.

Counsel for the Scottish government argued at the Supreme Court hearing in November 2024 that a person with a gender recognition certificate is “recognized in law” as having changed sex.

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Celebrations outside the Supreme Court in London on April 16, 2025. The court ruled unanimously that “the terms woman and sex in the Equality Act 2010 refer to a biological woman and biological sex.” The decision allows men who identify as women, even with a gender recognition certificate, to be excluded from single-sex spaces. Dan Kitwood/Getty Images

2. The Ruling

On April 15, the Supreme Court ruled that sex is rooted in biology, not in whether a person has chosen to identify as a certain gender.

Delivering the judgment, Lord Patrick Hodge, deputy president of the UK Supreme Court, said the central question is how the words “woman” and “sex” are defined in the Equality Act 2010.

“The terms woman and sex in the Equality Act 2010 refer to a biological woman and biological sex,” Hodge said.

This means that men who identify as women and who hold a gender recognition certificate may be excluded from single-sex spaces if “proportionate.”

The judges said that while the word “biological” does not appear in the definition of man or woman in the Equality Act, “the ordinary meaning of those plain and unambiguous words corresponds with the biological characteristics that make an individual a man or a woman.”

The decision states that if the word “sex” did not mean biological sex in the 2010 legislation, providers of single-sex spaces—including changing rooms, homeless hostels, and medical services—would face “practical difficulties” and that any other interpretation would render rules against discrimination on grounds of sexual orientation meaningless.

The court said this interpretation of the law does not disadvantage people who identify as transgender, who were described as a “potentially vulnerable group.”

They said the group is still protected from discrimination, and that if needed, they “would be able to invoke the provisions on direct discrimination and harassment, and indirect discrimination.”

The justices also said that transgender-identifying people are protected from discrimination on the grounds of gender reassignment.

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Campaigners who described themselves as women's rights activists stand next to the suffrage activist Dame Millicent Fawcett in Parliament Square in London on April 16, 2025. The Supreme Court ruled that sex is rooted in biology, not in whether a person has chosen to identify as the opposite gender. Dan Kitwood/Getty Images

3. Lawmakers Could Overturn It

The UK Supreme Court is the final court of appeal for all civil cases in the UK and all criminal cases originating in England, Wales, and Northern Ireland.

It also covers a limited number of criminal cases from Scotland, which technically has a separate legal system.

However, a Supreme Court judgment in the UK carries a lot less weight than it would in the United States.

Lawmakers in the UK are not bound by a codified constitution that can only be changed through a supermajority and other hurdles to ratification.

Rather, Parliament can effectively negate a Supreme Court ruling by voting in new legislation.

So a simple majority vote by lawmakers is all that would be required to repeal that legislation and pass a new law that requires males who identify as women to be treated exactly the same as women.

4. Unanswered Questions

Since the decision, many public bodies and institutions have updated their rules, while others are still waiting for clarity.

The Equality and Human Rights Commission, which is responsible for the promotion and enforcement of equality and nondiscrimination laws in the UK, is expected to put an updated statutory code of practice before Parliament by summer, and said it is working “at pace to incorporate the implications of [the] judgment” into the code for public bodies setting out their duties under the Equality Act.

This means that currently, despite the Supreme Court ruling, the situation is far from clear.

5. Police Strip Searches

The British Transport Police became the first public body to take action when it changed its strip search policy a day after the judgment, saying it had adopted a new “interim position” that will see transgender-identifying people in custody strip searched by an officer of the person’s biological sex.

This means that males in custody will be searched by male officers, while male officers who identify as trans women will no longer be able to search female detainees.

The National Police Chiefs’ Council has said it will be reviewing its policies, but “will need time to consider the full implications of the court’s decision, as will many other public bodies.”

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A British Transport Police officer patrols the main concourse at Waterloo Station in London on Dec. 20, 2020. The agency became the first public body to act after the Supreme Court ruling, updating its strip search policy to require that transgender-identifying individuals in custody be searched by an officer of their biological sex. Niklas Halén/AFP via Getty Images

6. Sports and Bathrooms

The head of the country’s equality watchdog has also said the ruling means that males can no longer use single-sex female toilets or changing rooms or compete in women’s sports.

Baroness Kishwer Falkner, Equality and Human Rights Commission chairwoman, said the ruling by the court was “enormously consequential,” and that she will pursue organizations that fail to update their policies.

“Single-sex services like changing rooms must be based on biological sex,” she told BBC Radio 4 on April 17.

“If a male person is allowed to use a women-only service or facility, it isn’t any longer single-sex, then it becomes a mixed-sex space.”

When asked if it is now the case that males cannot take part in women’s sports, Falkner said, “Yes, it is.”

However, Lord Jonathan Sumption, former Supreme Court justice, told the BBC that while the ruling means that organizations are allowed to exclude males from women-only facilities, they may not be obliged to do so.

The lawyer and historian said that in sports, for example, it would be down to individual governing bodies to decide who is allowed to compete in women’s sports.

“They could decide to allow trans women to compete on the same basis as biological women,” he said. “Some sporting authorities do, although I think that in light of the latest judgment, they would be wise to say so expressly in their rules.”

Women and Equalities Minister Bridget Phillipson has said that men who identify as trans women should use male toilets, but suggested that businesses should ensure that “they have appropriate provision in place,” which could mean unisex facilities.

She told BBC Radio 4 on April 22 that the Supreme Court ruling made it clear that “services should be accessed on the basis of biological sex.”

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A protester draped in a Union Jack flag sits outside unisex beach toilets during the

7. Health Care

The National Health Service guidance on single-sex wards currently states that “trans people should be accommodated according to their presentation, the way they dress, and the name and pronouns they currently use,” which means that males who identify as women will be offered beds in women-only wards.
Since the ruling, the National Health Service has said that its policy is under review.

8. Political Response

UK Prime Minister Keir Starmer has revised his position since the judgment, saying that a woman is an “adult female.”

In March 2022, while still in opposition, Starmer said, “A woman is a female adult, and in addition to that, trans women are women, and that is not just my view—that is actually the law.”

When asked on April 22 to repeat his previous statement that “trans women are women,” he said, “I think the Supreme Court has answered that question.”

When asked if that means he does not believe that a transgender woman is a woman, he told ITV West Country, “A woman is an adult female, and the court has made that absolutely clear.”
Kemi Badenoch, Conservative Party leader, called the decision a “victory.”

“Saying ‘trans women are women’ was never true in fact, and now isn’t true in law either,” she wrote on social media platform X on April 16.

“This is a victory for all of the women who faced personal abuse or lost their jobs for stating the obvious. Women are women and men are men: you cannot change your biological sex.”

Scottish First Minister John Swinney said the government in Edinburgh accepts the ruling, noting that “protecting the rights of all” will inform its response.

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UK Prime Minister Keir Starmer delivers a keynote speech during an event in London on April 24, 2025. Following the court ruling, Starmer revised his stance, stating that a woman is an “adult female.” Justin Tallis/WPA Pool/Getty Images

9. Campaigners’ Responses

For Women Scotland, which took the case to the Supreme Court, wrote on X, “Absolutely jubilant here, tears!”
“Harry Potter” author J.K. Rowling, who has been outspoken on the issue for many years, posted on X that campaigners had “protected the rights of women and girls across the UK.”

“It took three extraordinary, tenacious Scottish women with an army behind them to get this case heard by the Supreme Court,” Rowling wrote. “I’m so proud to know you.”

The LGB Alliance, a charity founded to support the rights of same-sex attracted people concerned about the promotion of gender identity ideology, and which provided a written submission in the case, said it is “delighted” with the “momentous” ruling.

However, campaigners on the other side have been scathing about the judgment. Charity group Stonewall said in a statement that there is “deep concern at the widespread implications” of the court ruling, which it said is “incredibly worrying for the trans community.”
Amnesty International UK labeled the ruling “disappointing.”

The group said the decision has “potentially concerning consequences for trans people,” but that it is “important to stress that the court has been clear that trans people are protected under the Equality Act against discrimination and harassment.”

Rachel Roberts contributed to this report.
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