What does trans mean and why is there a debate about transgender people's rights?

The UK Supreme Court ruled in April 2025 that the definition of a woman in equalities law is based on biological sex.

The decision, which applies to rules protecting people from discrimination in the workplace and wider society in England, Scotland and Wales, has caused heated debate about the implications for transgender people.

Businesses, public bodies and charities are among those reviewing their policies, particularly around single-sex spaces, such as toilets. A code of practice, produced by the Equality and Human Rights Commission (EHRC), is being considered by the government.

Northern Ireland follows anti-discrimination laws introduced before the 2010 Equality Act.

The Supreme Court judgment used a simple definition of biological sex: it is the sex recorded at birth. The court said this is widely used in law.

Critics argue that it is not a complete definition, so it is helpful to know some of the science behind the debate.

Only females can produce eggs and only males can produce sperm. Even if someone cannot have children they are still biologically male or female.

Most people have either male XY or female XX chromosomes. These chromosomes are in every human cell and help develop reproductive organs and other physical characteristics linked to being male or female.

There are some people who have rare conditions known as differences of sex development (DSD).

The NHS says this can mean a person has chromosomes usually associated with being female, or male, but reproductive organs and genitals that look different from usual. This may mean they have been registered at birth and raised as the opposite gender to their biological sex. People with such conditions are sometimes called intersex, but they are still biologically male or female.

Gender identity is a term used by some people to describe their sense of who they are.

A transgender person describes their gender identity as different from their sex at birth.

The Supreme Court ruling defines a transgender woman, in equalities law, as a biological male who identifies as a woman.

It says a transgender man is a biological female who identifies as a man.

Trans is a shorter way of saying transgender.

According to the NHS, gender dysphoria describes the "unease or dissatisfaction" some people feel about the mismatch between their biological sex and their gender identity. It says this can be "so intense it can lead to depression and anxiety and have a harmful impact on daily life".

People who do not consider themselves to have a solely male or female gender identity describe themselves as non-binary.

Some people do not accept the concept of gender identity and argue only biological sex can determine whether someone is a man or a woman.

Many transgender people live according to their chosen gender, changing their name, pronouns, how they dress and interact with the world.

These social and physical changes are elements of what is known as transitioning.

Some may take hormone medication to develop characteristics associated with their chosen gender.

For instance, this would help a biological female who identifies as a man deepen their voice and develop facial hair.

Some trans people have surgery to change their bodies further.

There are some people who later decide that transitioning was not, or is no longer right for them, although accurate figures for how many are not available. They are said to be de-transitioning, when they stop taking the medication, and return to living in a way that matches their biological sex.

NHS guidance says the medication causes some irreversible physical changes and, for those who take it for a long time, it may cause temporary or even permanent infertility.

Legal steps which can be taken by those transitioning include getting a gender recognition certificate (GRC) under the Gender Recognition Act 2004.

Obtaining a GRC means that someone's birth, marriage and death certificates will record their chosen gender identity, not their biological sex.

To get a GRC, applicants must usually meet the following criteria:

• have a gender dysphoria diagnosis
• provide evidence of living full-time in their acquired gender for at least two years
• make a declaration that they will live permanently in that gender
• be aged 18 or over
• pay a £6 fee

As of the end of September 2025, more than 10,250 gender recognition certificates had been issued in England, Wales and Scotland.

You do not need a GRC to update your driving licence, passport or medical records.

Non-binary is not recognised as a gender on legal documents in the UK.

The 2021 Census for England and Wales suggested that around 0.5% of people over 16 identified as transgender - 262,000 people.

However, this may have been an overestimate.

Concerns were raised that people who did not speak English as a first language may have misunderstood the relevant question.

The Census asked: "Is the gender you identify with the same as your sex registered at birth?"

The London Borough of Newham, which has one of the highest rates of non-English speakers (35%), had the highest proportion of people identifying as transgender (1.5%).

The ONS subsequentlydowngraded the data, describing it as "in development", but said the number who answered the question mistakenly waslikely "to be relatively small".

In April 2025, the UK Supreme Court gave its judgment in a long-running argument over how a woman should be defined under equalities law.

The justices ruled unanimously that when the 2010 Equality Act - which applies in England, Scotland and Wales - refers to "a woman" it means a biological female, and that the term "sex" means biological sex. It also said that sex is binary, meaning someone is either male or female.

The For Women Scotland campaign group brought the case against the Scottish government, after it introduced legislation which included some trans women in its definition of women.

The Scottish government argued that trans women with GRCs should be given the same sex-based rights as biological women.

The Supreme Court justices disagreed.

The judgment also said that if a space or service was designated as women-only, that did not mean it was open to a person who was born male but identifies as a woman, even if they have a GRC.

Trans people still have protections against harassment, discrimination and victimisation under the Equality Act, as gender reassignment is one of nine protected characteristics within the legislation.

Some women's rights groupshave saidthe Supreme Court judgment wasan important victory which safeguarded the rights of biological women.

In the hearing, For Women Scotland argued that an interpretation of equality law which ignored biological sex had "made a nonsense" of hard-won protections for women.

It said, for instance, that letting trans women join women-only shortlists in politics or use single-sex spaces undermined attempts to tackle deep-rooted discrimination faced by biological females.

Sex Matters, another group involved in the case, called the ruling incredibly important "for the half of humanity who need single-sex spaces".

The judgment was also welcomed by some lesbian, gay and bisexual campaigners, with the LGB Alliance describing it as a "watershed moment for women".

It said the ruling confirmed that, for instance, lesbians who wanted to form "associations of any size were legally entitled to exclude men" including trans women who have GRCs.

Groups, such as TransActual and Stonewall, described the Supreme Court ruling as "devastating" for transpeople and said it created confusion not clarity.

They warned it would leave trans people unsure of what to do, given they had previously felt able to use single sex facilities, such as public toilets or domestic violence refuges, that matched their acquired gender.

Also among their concerns was the impact on people with GRCs.

This is because the relevant legislation says a person with a certificate becomes "for all purposes their acquired gender", with a few limited exceptions.

However, under equality law, the Supreme Court ruling means they would still be regarded as being their birth sex.

Among those to raise this issue is Dr Victoria McCloud, the UK's only judge to say publicly that she is transgender.

Shortly after the judgment, Dr McCloud submitted a legal challenge against the ruling to the European Court of Human Rights. She believes there was a failure to consider the rights of transpeople.

Dr McCloud, who stood down as a judge in 2024, holds a GRC. She says that means "I am a woman for all purposes in the law", because her birth certificate says she is a woman.

However, she says that the Supreme Court judgment means: "I'm a man for the Equality Act 2010. So, I have to guess on any given occasion which sex I am."

The EHRC, which oversees equalities law in the UK, has to provide practical advice to businesses and services about how the Supreme Court ruling should be applied.

Its proposed code of conduct, a 300-page document, is being considered by the government.

In January, Equalities Minister Bridget Phillipson blamed delays in publishing the guidance on the watchdog's "slow response" to government requests for further information. The EHRC said the guidance was "both legally accurate and as clear as it is possible to be".

The guidance, which was seen by BBC News after it was leaked, says single-sex spaces should only be open to people of the same biological sex, otherwise they cease to be single-sex areas.

That would mean, for instance, that a biological male who identifies as a woman would not be able to use women's toilets and changing rooms.

It says that, if there are concerns, decisions about access to single-sex spaces may need to be based on how someone looks. There is no type of official document in the UK which provides evidence of sex.

However, the proposed guidance says transgender people, who are also protected by equalities law, should be treated with dignity and respect.

It says that if a transgender person is excluded from a space, the organisation should consider alternatives and that it would not be proportionate to leave them without essential services, such as toilets.

However, it acknowledges that providing alternatives may not always be possible due to space constraints or cost.

The draft guidance also says that "discrimination or harassment could occur" if a person is questioned about their sex and that such questions should be asked "discreetly". Instances of excluding someone from a service should also be handled "as sensitively as possible".

TransActual described the leaked guidance as "a license to discriminate based on looks, plain and simple". It warned that staff at cinemas, hospitals, bars and cafes would have to try to judge whether people are transgender "based on appearance alone".

The EHRC had previously issued interim guidance, which has since been withdrawn, stating that in places like hospitals, shops and restaurants, single-sex toilets should only be used by people of the same biological sex. Legal action against these guidelines argues that they are "overly simplistic".

In response to the Supreme Court ruling, some organisations have already introduced new policies.

Girlguiding, which oversees girl guide groups in the UK, is banning trans girls from joining. The Women's Institute said that it will no longer offer membership to transgender women from April 2026.

The EHRC has also said that it would issue guidance for sport "in due course". Some sporting bodies have already announced changes.

In May 2025, the Football Association and the England and Wales Cricket Board said transgender women would no longer be able to compete in women's and girls' games.

Sports such as athletics, rowing and rugby had already banned trans women from female categories.

In summer 2025, World Boxing and World Athletics introduced mandatory sex testing for women's categories at their events.

The Equality Act does not apply in Northern Ireland. As a result, its Equality Commission said there were "significant legal uncertainties" following the Supreme Court ruling. The body issued initial guidance for employers and service providers and said it would seek a declaration from the High Court about how to interpret the decision.

In 2024, NHS England began introducing new gender clinics for children questioning their gender identity. Three have opened, with centres in London, the North West and South West. Another five specialist regional centres are due to open in the near future.

The NHS said these will bring together specialist clinicians, including experts in child health, hormone treatment and mental health, and that psychological support will be a major focus.

The opening of new clinics follows a landmark review into children's gender services by paediatrician Dr Hilary Cass, published in 2024. This made serious criticisms of the London and Leeds-based Gender Identity Service (Gids) run by the Tavistock clinic. At the time, this provided the only children's service available in England.

Trans groups have criticised the Cass report, questioning its methodology and saying that Dr Cass is not an expert in gender dysphoria.

Different services are available in other parts of the UK:

• Young people in Scotland can get a GP referral to the gender service at the Sandyford clinic
• In Wales, children or teenagers can be referred or refer themselves to a specialist gender identity clinic
• Those in Northern Ireland who want to talk to a specialist about their gender identity can use the Knowing Our Identity service

The Cass Review also raised concerns about the lack of clinical evidence on the safety of puberty-blocking drugs in the treatment of children who were questioning their gender.

Puberty blockers, also known as puberty suppressing hormones, are used to delay or prevent puberty happening.

In 2024, the government brought in a UK-wide ban on these drugs being prescribed for gender treatment, on the NHS or privately, to children and young people.

The Cass review recommended that puberty blockers should only be prescribed as part of a clinical trial which could gather evidence of their risks and benefits in children's gender care. In November, details of that trial were announced.

It will involve about 220 children aged between 10 and 15 who are going through puberty and will examine the impact of the drugs on their physical, social and emotional wellbeing.

The study team said those taking part would be well supported and would need to demonstrate a sufficient understanding to give their consent.

Some clinicians and campaigners have questioned whether the trial is ethical. Legal letters were sent to the organisations involved in setting it up, in December 2025. They have called for an immediate halt to the trial.

Adult services were also criticised by the Cass Review which found that, in some clinics, assessments were not long enough, there was chaotic administration and the process of getting patients consent was inadequate.

A follow-up inquiry into gender dysphoria clinics in England, by Dr David Levy and published in December 2025, found that there were "unacceptable" waiting times, inconsistent care and a lack of data on medical outcomes for patients.

There are currently 12 gender dysphoria clinics for adults operating in England. Three opened after the Levy review started in 2024, so were not part of it.

There are four NHS gender identity clinics for adults in Scotland and one in Northern Ireland. Wales has one clinic and several local teams.

In addition to NHS clinics, there are a number of private gender clinics operating both in the UK and other countries.