This guide is maintained as a current resource for July 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
Comprehensive guide to using comparators in workplace discrimination cases under UK law. Explains what comparators are, real and hypothetical comparisons, when they are required, how tribunals assess them, and practical guidance for discrimination claims in employment tribunals.
In many workplace discrimination claims under the Equality Act 2010, the use of comparators is central to establishing whether an employee has been treated less favourably because of a protected characteristic such as age, sex, race, disability or religion. Comparators help tribunals assess whether the treatment of a claimant was unfavourable in ways that are unlawful. This guide explains what comparators are, when and how they are used, what counts as a valid comparator, issues with hypothetical comparators, and practical steps for presenting comparator evidence in an employment tribunal claim.
What Is a Comparator?
A comparator is a person whose treatment in similar circumstances can be compared with that of the claimant to assess whether the claimant experienced unfavourable treatment because of a protected characteristic. In direct discrimination claims, the statutory test requires showing that the claimant was treated less favourably than a comparator who does not share the claimant's protected characteristic. This comparison must be “like with like” in all material respects except for the protected characteristic.
For example, in a sex discrimination claim, a female employee might compare her treatment and opportunities with those of a male colleague who is otherwise similar in role, experience and qualifications.
How Comparators Are Defined in Law
The Equality Act 2010 and associated explanatory notes establish when a person can be treated as a comparator. Section 79 of the Act explains that comparators can include employees at the same establishment or, where common terms and conditions apply, employees at different establishments under the same employer. Comparators may also include predecessors or successors in a role in some circumstances.
The comparator test is primarily used in direct discrimination cases under section 13 of the Equality Act, where the law states that someone discriminates if they treat another person less favourably because of a protected characteristic. To show this, a claimant typically identifies a comparator treated more favourably in similar circumstances.
Real Versus Hypothetical Comparators
Real Comparators
A real comparator is an actual person who:
- Works for the same employer (or associated employer) as the claimant;
- Has similar responsibilities, skills, experience and job characteristics;
- Does not share the claimant's protected characteristic; and
- Received more favourable treatment in the same or materially similar circumstances.
Tribunals assess whether the differences in circumstances between the claimant and the comparator are material to the issue in dispute. Only differences that the employer took into account are relevant; discriminatory differences themselves are generally ignored in defining the comparator's circumstances.
Hypothetical Comparators
Where there is no suitable real comparator, tribunals may consider a hypothetical comparator - a constructed example of how a person without the protected characteristic would have been treated in identical circumstances. Hypothetical comparators are recognised as a tool to test less favourable treatment, especially where direct comparison with a real colleague is impracticable.
For example, if an employer says a woman would have been paid more “if she were a man,” and there is no male employee in the same role, the tribunal can consider how a male comparator would have been treated. This principle has been codified in equal pay provisions (section 71 Equality Act) and reflects longstanding case law.
However, hypothetical comparators are applied cautiously, and their construction depends on the specific facts and evidence. A claimant must convincingly show that, but for the protected characteristic, the comparator would have been treated more favourably in otherwise identical circumstances.
When Comparators Are Not Required
In certain discrimination contexts, a comparator is not required to prove discrimination:
- Pregnancy and maternity discrimination: The law treats discrimination linked to pregnancy or maternity without the need for a comparator because the protected characteristic itself establishes the unfavourable treatment.
- Harassment and victimisation: These forms of discrimination under the Equality Act do not rely on a comparator test; instead, the focus is on the nature and impact of the conduct.
- Clear discriminatory conduct: In egregious cases where discriminatory behaviour is obvious on its face (such as discriminatory language), tribunals may find discrimination without a comparator as part of the broader factual assessment.
Selecting an Appropriate Comparator
For a comparator to be effective evidence in a tribunal:
- The comparator must be in materially the same circumstances; relevant factors include job role, responsibilities, terms and conditions, experience and location where applicable.
- Differences not related to the protected characteristic should not materially affect how the comparator was treated.
- For equal pay claims, work must be of equal value or like work for a comparator to be valid.
Tribunals often examine the context of treatment to decide whether the comparator genuinely mirrors the claimant's situation, excluding only the protected characteristic.
Practical Use of Comparator Evidence
Comparators are primarily used to show less favourable treatment in direct discrimination claims. Typical examples include:
- A colleague without the claimant's protected characteristic receiving a promotion, training or pay increase that the claimant was denied.
- A real or hypothetical worker being treated differently in disciplinary or redundancy procedures.
Claimants should gather evidence to identify suitable comparators where available, such as records of how others were treated and employment data. Tribunals may also infer comparative treatment where explicit examples are lacking, considering the overall pattern of conduct.
Limitations and Considerations
Comparator evidence is a useful tool but can be challenging:
- Identifying an appropriate real comparator may be difficult, particularly in small workforces or unique roles.
- Differences unrelated to the protected characteristic can undermine a comparator comparison if they materially affect treatment.
- Hypothetical comparators require careful construction and credible supporting evidence; tribunals will scrutinise whether the hypothetical reflects how a comparator would genuinely be treated.
Some commentators have noted that rigid reliance on comparators may not fully reflect modern workplace realities and can create hurdles in proving discrimination where direct evidence is limited, though comparator tests remain central to most direct discrimination claims.
Summary
In workplace discrimination claims under the Equality Act 2010, comparators are central to demonstrating less favourable treatment in direct discrimination cases. A comparator must be materially similar in circumstances to the claimant, differing only by the protected characteristic at issue. Where no real comparator exists, tribunals can consider hypothetical comparators to assess whether unfavourable treatment occurred. Comparators are not required for pregnancy and maternity discrimination or in harassment and victimisation claims. Presenting clear comparator evidence - whether real or hypothetical - strengthens a discrimination claim by allowing tribunals to assess objectively whether the claimant was unfairly treated due to a protected characteristic.
