On 16 April 2025, the Supreme Court ruled on the issue of whether a person who has been issued with a full Gender Recognition Certificate is a woman for the purposes of protections under the Equality Act 2010. This marked the culmination of a long-running legal battle between the Scottish Government and For Women Scotland Ltd, challenging previous rulings by the Scottish courts that gender is ‘not limited to biological or birth sex’.
After passing to the UK’s Supreme Court, the ruling on the proper interpretation of the 2010 Act is important as it means the issue is no longer limited to Scottish law and instead affects interpretation of the Act which applies across Great Britain – but not in Northen Ireland.
The outcome could have gone one of three ways:
1. In favour of the Scottish Government, who believe that ‘sex’ is either biological sex / birth sex or ‘certified sex’ as defined by the Gender Recognition Act 2004; or
2. In favour of For Women Scotland Ltd, who challenged that ‘sex’ can only be biological sex / birth sex ; or
3. Where judges say it is not their role to pass an interpretation of a law passed by politicians in the UK Parliament
The Ruling
The Supreme Court ruled unanimously that the Equality Act 2010 definition of a woman is based on biological sex. Lord Hodge gave the judgement ruling saying that it was a ‘unanimous decision’ of the five judges.
ICB wants to highlight issues that may concern members as a result of the ruling.
What are the Implications for Gender Pay Gap Reporting?
The 2017 reporting Regulations are written under the Equality Act 2010. This requires qualifying employers to report, amongst other indicators, on the mean and median average pay of relevant employees. Whilst terms such as ‘ordinary pay’ and ‘bonus pay’ are expressly defined, there is no such express definition of ‘male’ or ‘female’.
Therefore, the Supreme Court ruling has no implications for Gender Pay Gap reporting and the statutory guidance ‘Preparing your data’ does not need to be amended, especially the section ‘Recording employees’ gender’. This reads:
It is important for you to be sensitive to how an employee identifies their gender. The gender pay gap regulations do not define the terms ‘men’ and ‘women’.
You should not single out employees and question them about their gender. To reduce the risk of this, try to use information employees have already provided, such as in HR or payroll records.
If this information is unavailable or unreliable, find a way to allow employees to confirm or update their gender. For example, invite them to check their recorded gender and update it if needed.
If an employee does not self-identify as either gender, you can exclude them from your calculations.
So, even though the Supreme Court has made a ruling, it remains the fact it is up to employers to identify the gender of the employee, using the gender (if any) that the employee identifies with at the snapshot date of the report. This may not be the same as the gender reported to HMRC on RTI submissions.
In that regard…
What are the Implications for RTI Submissions?
When an employee has been issued with a full Gender Recognition Certificate under the Gender Recognition Act 2004, they are legally allowed to change their recorded gender and to benefit from any rights and responsibilities that are associated with their acquired gender. This could affect their liability to pay National Insurance Contributions, however, the State Pension age (SPa) is aligned at 66 for both men and women. So, the Supreme Court ruling has no impact.
However, it is worthwhile pointing to HMRC’s guidance in reporting changes of gender, also unaffected by the Supreme Court ruling. This says that if the employee changes name and gender, there is the requirement for separate Full Payment Submissions (FPSs). Reporting all of these changes in one FPS may result in HMRC’s systems believing that this is a new employee and create a duplicate employment.
What are the Implications for Employers?
The ruling that, for the purposes of the 2010 Act, a woman is defined by biological sex / birth sex rather than certified sex granted by a Gender Recognition Certificate may mean employers have to re-think policies and guidance that rely on a consistent biological definition of sex, for example;
- Single-sex spaces and services in the workplace (bathrooms and changing rooms etc);
- Equal pay claims;
- Maternity policies;
- Sporting events;
- Communal accommodation; and
- Medical care / provision
However, the ruling does not leave trans women (or men) unprotected, as Lord Hodge was clear to state. Gender reassignment remains a protected characteristic in the 2010 Act meaning individuals remain able to bring claims if they are discriminated or harassed.
It is true, however, that there is an uncomfortable interaction between equality law (the 2010 Act) and gender recognition (the 2004 Act). Overall, though, the ruling does give employers certainty that will allow them to make legally-compliant decisions, policies and procedures.
