Equal pay is the right for men and women to be paid the same when doing the same, or equivalent, work. It has been an aspect of UK sex discrimination law since 1970, and the law is now incorporated into the Equality Act 2010. However, a significant pay difference between male and female employees still exists.

This factsheet offers a broad outline of equal pay law looking at the role of 'comparators', how claims are dealt with by employment tribunals and the employer's right to a ‘material factor’ defence. It also suggests good employment practices.

Explore our stance on gender equality in more detail, along with actions for Government and recommendations for employers.

Equal pay is the right for men and women to be paid the same for the same, or equivalent, or work of equal value. It’s an aspect of UK sex discrimination law which has been in force for 50 years. Where men and women are not receiving equal pay, the employer must prove that the reason isn’t gender-related.

Equal pay or pay discrimination is not the same as having a gender pay gap. The gender pay gap is calculated by taking all employees in an organisation and comparing the average pay between men and women. Equal pay rules outlaw pay differences in men and women’s pay for same or similar work. It’s possible for an employer that treats its women fairly in terms of pay to have a large gender pay gap, and for an organisation that treats its female workers unfairly to have a small gap. Gender pay gap reporting has become a legal requirement for all UK organisations with 250 employees or more.

The law on equal pay in the UK was first introduced by the Equal Pay Act 1970. It is now part of the Equality Act 2010 which applies in Great Britain.

The law gives a woman the right to be paid the same as a man (and vice-versa) for

  • Like work- two employees who are doing the same or broadly similar roles, or

  • Work rated as equivalent by analytical job evaluation study - could be totally different jobs which have been given the same rating as the result of an analytical job evaluation, or

  • Work of equal value - when there are two jobs that are very different, but the employee claims that they require a similar level of skill and ability. For example, a female cook comparing her work to that of painters, insulation engineers and joiners who work for the same organisation.

The right to make a claim under equal pay legislation applies to employees and to anyone with a contract to carry out any work personally.

The Equality Act also introduced legislation relating to pay secrecy clauses. It’s unlawful to prevent or restrict employees from discussing their pay. Any pay secrecy clauses in a contract of employment are unenforceable, and if an employee suffers any detriment from discussing their pay, this will be unlawful. This only applies to discussing pay within the organisation. An employer can require employees to keep their pay confidential from outside bodies, such as a competitor organisation.

If an employer is found guilty of pay discrimination, then it must carry out an equal pay audit unless an exception applies. The audit must be published on the employer’s website and be left there for three years. If an employer fails to comply, a tribunal can impose a penalty of up to £5,000.

The Equality and Human Rights Commission has published a range of guidance on all aspects of the Equality Act, including a Code of practice on equal pay. Whilst not legally binding documents, the codes give important guidance on good practice and failure to follow them may be considered by tribunals or courts. CIPD members can find out more in our Equal pay law Q&As.

Equal pay claims are usually dealt with by an employment tribunal. An employee may bring a claim up to six months after leaving employment. There have also been some successful equal pay claims in the civil courts, where the time limit for bringing a claim is six years. Historically, employees have used an equal pay questionnaire to obtain information for their claim from employers. However, this has been replaced with non-statutory Acas guidance for employees to follow to find out whether they have received equality of terms in accordance with the Equality Act 2010.

The person bringing the claim must show that, on the face of it, he or she is being paid less than a person of the opposite gender doing the same work. The employer must then give a non-discriminatory reason for the difference in pay.

To bring an equal pay claim, the person bringing the claim must point to a ‘comparator’. A comparator is a person of the opposite gender, working for the same employer, doing like work (or work rated as equivalent, or work of equal value) who is paid more, or has more beneficial terms and conditions of employment, than the claimant.

The comparator can be someone working for the employer at the same time or in the past (a predecessor) but not someone employed afterwards (a successor). A comparator may even work for another employer as long as the inequality in pay is attributable to a single source (for example, in the public sector where there are employees doing similar work in several different locations). Under the Equality Act, if a woman cannot find an actual comparator, she may consider a direct sex discrimination claim relating to pay instead, in which case pay may be compared to a hypothetical male comparator.

The law doesn’t allow consideration of the equality of a contract of employment as a whole – so it’s not a defence to a claim to say that a lower hourly rate of pay is compensated by, for example, a better annual holiday entitlement. The contracts of employment of the claimant and the comparator must be compared clause by clause. The claimant can effectively ‘pick and choose’ the most beneficial provisions from their own and the comparator’s contracts.

The tribunal can order:

  • A declaration of the claimant’s rights.
  • Equalisation of their contractual terms for the future.
  • Arrears of pay for up to six years (five years in Scotland).
  • An equal pay audit.

To defend a claim, an employer must be able to show that:

  • The person bringing the claim and the comparator (or hypothetical comparator) are not engaged in ‘like work’, or
  • A bona fide and non-discriminatory job evaluation scheme has been conducted and the work is not ‘rated as equivalent’, or
  • The work is not of ‘equal value’, or
  • Any difference in pay is due to a material factor, or difference other than the difference of gender.

There are special rules of employment tribunal procedure for dealing with claims for work of equal value. This might involve the tribunal appointing an independent expert to investigate and report back.

The Material Factor defence

The employer has a defence to an equal pay claim if it can show that, although men and women are being paid differently for the same or similar work, the reason is due to a ‘material factor’. This material factor must not itself contain any element of sex discrimination. A good example of a material factor would be a London Weighting allowance.

If there is a ‘material factor’ defence, it must not put one sex at a disproportionate disadvantage. If there is such a disadvantage, then the defence must be objectively justifiable as a proportionate means of achieving a legitimate aim. For example, it could be a material factor if a man was more experienced than the woman. However, if the woman found it more difficult to gain the experience because of career breaks for childcare reasons, then the employer must show that it was justifiable to reward the additional experience by paying the man more.

Difficulties arise when the claim is for work of equal value between a woman and a man doing different jobs. Historical reasons for the different pay levels is not enough to establish the defence. However, an employer might be able to show the wage differences are a result of skill shortages, or for night rather than day work.

In areas such as local government and the NHS, there is often a long history of women working in comparatively poorly paid areas of work, whose jobs have subsequently been found to be of equal value to work done by more highly paid men. Similar claims have arisen in the private sector too, for example in 2018 the Court of Appeal held that female supermarket staff working in store could compare their wages to male warehouse staff who were being paid more. This has been predicted in the press to expose the supermarkets to up to £8 billion in compensation payments. Where women have not been adequately compensated for unequal pay in the past, they may bring individual claims against employers for back pay.

Employers must ensure their pay structures meet the requirements of the Equality Act 2010. The Code of practice on equal pay recommends equal pay reviews, reports or audits as the most appropriate method of delivering a pay system free from gender bias. The Equality and Human Rights Commission provides an online toolkit for organisations with 50 or more employees to help them carry out an equal pay audit. Another EHRC guide helps small and medium sized organisations to carry out an equal pay review.

To ensure compliance with equal pay legislation across a business where there might be many different job types and pay structures, employers could set up a job evaluation scheme. However, great care should be taken to ensure that the scheme doesn’t contain in-built gender bias based on assumptions about the levels of skills etc, required for various jobs. Read our market pricing and job evaluation factsheet.

Alongside good practice, inequalities in pay between men and women can be addressed by:

  • Wider availability of flexible working.
  • Eliminating of discrimination against part-time workers.
  • Building an awareness within the business of other barriers to the progress of women.
  • Ensuring a similar focus on development and career progression for those working part-time as for full-time employees, as this is often an area that's often neglected.

By identifying unjustifiable differences in the earnings of male and female employees, people professionals can help reveal underlying indirect discrimination that may otherwise go unnoticed and prevent their organisations from making the best use of its talent.


Acas - Equal pay

GOV.UK - Employers: preventing discrimination

Equality and Human Rights Commission - how to implement equal pay

Government Equalities Office

Equal Pay Portal

Books and reports

INCOMES DATA SERVICES (2017) Equal pay. Employment law handbook. London: Thomson Reuters.

RUBENSTEIN, M. (2020) Discrimination: a guide to the relevant case law. 33rd ed. London: Michael Rubenstein Publishing.

WOMEN AND WORK COMMISSION (2009) Shaping a fairer future: a review of the recommendations of the Work and Women Commission three years on. London: The Commission.

Journal articles

JONES, A. (2017) Tackling the root causes of mass equal pay claims. People Management. 4 October.

MARGOLIS, D. and PAREKH, R. (2019) What can businesses do to ensure equal pay? People Management (online). 26 March.

THOMAS, R. (2020) How to conduct an equal pay analysis. People Management (online). 25 February.

CIPD members can use our online journals to find articles from over 300 journal titles relevant to HR.

Members and People Management subscribers can see articles on the People Management website.

This factsheet was last updated by Lisa Ayling, solicitor and employment law specialist, and by Charles Cotton.

Charles Cotton

Charles Cotton: Performance and Reward Adviser

Charles directs the CIPD's performance and reward research agenda. He has recently led research into: how employers can help improve their employees’ understanding of their personal finances; how front line managers make and communicate reward decisions to their employees; how employers manage the risks around reward; how private sector employers can build the business case for workplace pensions; how employees form their attitudes to pay; and how the annual pay review process can become more strategic. 

He is also responsible for the CIPD’s public policy reward work and has given evidence to select committees on banking pay, redundancy awards as well as responding to various consultations, such as on pensions, retirement and MPs’ expenses.

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