Gender pay gap reporting is a legal duty for any employer with 250 or more employees on its snapshot date. Private and voluntary sector employers use a snapshot date of 5 April and must report by 4 April the following year. Most public authorities use 31 March, with a deadline of 30 March. Employers report six figures on the government's gender pay gap service and publish them on their own website, with a signed written statement in the private and voluntary sector. From April 2026 employers can also publish a voluntary action plan, which the government expects to become mandatory, subject to legislation, from spring 2027.
Who has to report
The test is headcount, not full-time equivalents, on the snapshot date. Under the Equality Act 2010 (Gender Pay Gap Information) Regulations 2017, a "relevant employer" is one with 250 or more employees on the snapshot date. The government's guidance says the headcount includes:
- Employees. Everyone with a contract of employment, including part-time staff, job-sharers and people on leave;
- Some self-employed people. Those who must perform the work personally and cannot subcontract it;
- Salaried partners. Partners on a salary or LLP members treated as employees for payroll purposes count towards the headcount, but are left out of the calculations.
Agency workers count towards the agency's headcount, not the hirer's. Each legal entity in a group reports separately if it meets the threshold. A group may also publish combined figures voluntarily. If you have more than one payroll, the data must be merged into one set of figures.
Snapshot dates and deadlines
| Employer type | Snapshot date | Reporting deadline |
|---|---|---|
| Private, voluntary and other public authority employers | 5 April | 4 April the following year |
| Most public authority employers (government departments, local authorities, NHS bodies, most schools) | 31 March | 30 March the following year |
So a company with 250 or more employees on 5 April 2026 must report by 4 April 2027. Public authorities in Scotland and Wales follow separate rules. Ordinary pay is taken from the pay period that includes the snapshot date. Bonus pay covers the 12 months ending on the snapshot date.
The six calculations
Regulation 2 of the 2017 Regulations requires these figures:
- Mean gender pay gap in hourly pay, for full-pay relevant employees;
- Median gender pay gap in hourly pay, for full-pay relevant employees;
- Mean bonus gap, for all relevant employees;
- Median bonus gap, for all relevant employees;
- Proportion of men and women receiving a bonus;
- Proportion of men and women in each pay quartile: lower, lower middle, upper middle and upper.
A "full-pay relevant employee" is one who is not being paid at a reduced rate or nil because of leave during the relevant pay period. Someone on statutory maternity pay or reduced sick pay is therefore left out of the hourly pay figures but kept in the bonus figures. Pay is measured gross, after salary sacrifice and before tax, National Insurance and employee pension contributions. Overtime, redundancy pay and payments for untaken leave are excluded from ordinary pay. Figures can be reported as whole numbers or to one decimal place.
Worked example: mean and median
The gap is expressed as a percentage of men's pay. A positive figure means women are paid less on average; a negative figure means men are.
Suppose the mean hourly pay of full-pay relevant men is £20.00 and of women is £17.50. The mean gap is (£20.00 − £17.50) ÷ £20.00 × 100 = 12.5%. If the median man earns £18.00 an hour and the median woman £17.10, the median gap is (£18.00 − £17.10) ÷ £18.00 × 100 = 5.0%. Where there is an even number of men or women, the median is the average of the two middle values.
A large mean gap alongside a smaller median gap usually points to a small number of very high earners, mostly men, at the top of the distribution. That is the kind of point a supporting narrative should explain.
What you publish and who signs it
- Gender pay gap service. Submit the six figures, plus the name and job title of the person who signed the written statement;
- Your own website. Publish the figures where employees and the public can see them, and keep them online for at least three years;
- Written statement. Private and voluntary sector employers must confirm the figures are accurate. A company director signs for a company, and a designated member for an LLP;
- Supporting narrative. Optional, but it is where you explain the gap and what you are doing about it.
You remain responsible for accuracy even if a third party does the calculations.
Late reporting, enforcement and what is changing
Failing to report by the deadline is unlawful. The Equality and Human Rights Commission can take enforcement action, which can lead to court orders and fines. The gender pay gap service also shows a public "late badge" against employers that miss the deadline. If your headcount falls below 250, update your reporting requirement on the service to avoid a late badge.
Two changes come from the Employment Rights Act 2025:
- Equality action plans. Section 33, in force since 6 April 2026, inserts a power into the Equality Act 2010 to require employers with 250 or more employees to publish plans on gender equality, expressly including the gender pay gap and support for employees going through the menopause. The power only bites once regulations are made, and none had been made at the time of writing, so plans remain voluntary for now and can be published on the service;
- Outsourced workers. Section 34 allows regulations to require employers to name the suppliers of contract workers. It is not yet in force.
Sources: Equality Act 2010 (Gender Pay Gap Information) Regulations 2017; gov.uk: Gender pay gap reporting guidance for employers; gov.uk: Creating an action plan; Employment Rights Act 2025, section 33 and section 34. Related guides: ethnicity pay gap reporting and the EU Pay Transparency Directive.
The numbers are only as good as the payroll data behind them. Acumon's payroll audit and payroll management teams can extract and check snapshot-date pay and bonus data before you submit.