Gender Pay Gap Reporting Guidance (2026) — recording sex + the GRC-holder data firewall

In brief

GEO/WEU statutory guidance on gender-pay-gap reporting. Post-FWS, GPG figures are recorded on biological sex; a GRC holder is recorded by BIRTH sex for the GPG calculation. Because this can OUT a stealth GRC holder, the guidance relies on GRA 2004 s.22's 'required by law' / non-identifying exceptions and prescribes mitigations: process to the LEAST extent necessary; a single named person with confidential access; anonymise the published output; do NOT single anyone out; do NOT demand documents/evidence of sex; apply the SAME process to all employees. THE DECISIVE TOOLKIT POINT — a purpose-limitation firewall: this birth-sex data is ring-fenced to the GPG reporting purpose and MUST NOT be reused as evidence to exclude a person from a single-sex service or facility, or for any other operational HR decision (UK GDPR Art 5(1)(b) purpose limitation). The lawful posture is 'do it, then ring-fence it' — an employer in scope cannot opt out of GPG reporting, but must firewall the data. A concrete worked instance of the OEO Equality Impact Assessment (EQIA-003) involuntary-disclosure finding.

Key provisions

• recording-employees-sex — Recording employees' sex — biological-sex basis; GRC holders by birth sex: Step 1 'Recording employees' sex': GPG figures are based on biological sex (post-FWS). A GRC holder is recorded by birth sex for the GPG calculation, not acquired gender. This is a legally-mandated internal processing of special-category data that can out a stealth GRC holder.
• gra-s22-reliance-and-mitigations — GRA s.22 reliance + the mandatory mitigations: The processing relies on GRA 2004 s.22's 'required by law' / non-identifying exceptions. The guidance prescribes mitigations: process to the least extent necessary; a single named person with confidential access; anonymise the published figures (watch small-headcount re-identification); do not single anyone out; do not demand documents; apply the same process to everyone.
• purpose-limitation-firewall — KEY — the purpose-limitation firewall (never repurpose GPG birth-sex data): The birth-sex data recorded for GPG reporting is ring-fenced to the GPG purpose (UK GDPR Art 5(1)(b)). It must NOT be reused as evidence to exclude a person from a single-sex service/facility, nor for any other operational decision. Keep it separate from operational HR fields, storage-limited, not queryable.

When relevant

Employer in scope of GPG reporting (250+ employees) handling GRC-holder sex data; any DPIA / EqIA touching gender or sex data fields; Quinn questions on recording sex, GRC confidentiality, or whether HR sex data can inform single-sex-service decisions.