The Equality and Human Rights Commission (EHRC) has published interim guidance for employers following the UK Supreme Court's ruling on the legal definition of "sex" in the Equality Act 2010. The guidance is explicitly provisional. That label matters for HR teams deciding how quickly to rewrite policies.

Osborne Clarke's latest UK Employment Law Coffee Break sets out what the interim guidance covers, how the "all reasonable steps" defence operates in discrimination claims, and recent developments on incentives. The briefing does not claim the guidance settles every open question. It does not.

What does the interim guidance change?

The EHRC document responds directly to the Supreme Court judgment on the meaning of "woman" and "sex" under the Equality Act. Until the court ruled, employers operated on the assumption that Gender Recognition Certificates altered a person's legal sex for all purposes under the Act. The judgment removed that assumption.

For people-process decisions, the immediate touchpoints are practical ones: single-sex facilities, occupational requirements, and how equality policies define the protected characteristic of sex. The guidance is interim, which signals that a fuller code of practice is expected before employers can treat the position as fixed. Any policy rewrite done now may need revision again. Osborne Clarke's takeaways should be read with that caveat attached.

The jurisdiction is Great Britain, and the underlying statute is the Equality Act 2010. No new compliance deadline accompanies the interim guidance itself. That absence cuts both ways: no immediate deadline, but no safe basis for delay either, since tribunals will apply the Supreme Court's ruling to conduct now.

How does the 'all reasonable steps' defence work?

The briefing also examines the "all reasonable steps" defence, available to employers in Great Britain when an employee discriminates in the course of employment. The defence succeeds only where the employer can show it took every reasonable step to prevent the discriminatory act.

What counts as reasonable is fact-specific. Tribunals weigh factors such as the size and resources of the employer, the nature of the workforce, and the steps actually taken — training, policies, monitoring, enforcement. The defence fails where an employer identifies a step it could have taken and did not.

The connection to the EHRC guidance is direct. Updated training and updated policies on sex as a protected characteristic are the kind of steps an employer will struggle to explain omitting after publication of national guidance. Guidance does not create new law. It does create a benchmark against which an employer's steps will be measured.

The one-sentence takeaway: employers that delay updating policies and training until the final code of practice risk arguing after the fact that they took all reasonable steps, while the record shows they took none.

What is in the incentives update?

Osborne Clarke's third strand covers its latest update on incentives, meaning the arrangements employers use to reward and retain staff. The firm frames this as part of the same briefing for HR decision-makers rather than as a standalone legal development.

The detail sits in the full briefing. For a general HR audience, the relevant question is capability and process: do current incentive structures need review in light of any legal change, or are they untouched by the Equality Act ruling? The headline does not say. Readers should check the original before adjusting any scheme.

What should employers do now?

The realistic sequence is straightforward. Read the interim guidance. Audit where policies reference sex, single-sex spaces, or occupational requirements. Brief managers who field day-to-day questions. Record what was done and when, because the record is the evidence if the "all reasonable steps" defence is ever tested.

The EHRC has promised a fuller, statutory code of practice to follow. Until it arrives, employers in Great Britain are working with provisional guidance on a settled judgment — a position that rewards early action but does not punish careful review.