Comparator Evidence in Discrimination Claims

Comparator evidence is a central concept in UK discrimination law. In Employment Tribunal claims, it is often used to assess whether a person has been treated less favourably because of a protected characteristic under the Equality Act 2010.

A “comparator” is another person used as a reference point to determine whether discrimination has occurred. The comparison helps tribunals decide whether the claimant has been treated differently in similar circumstances and whether that difference is linked to a protected characteristic such as sex, race, disability, age, or religion.

This article explains how comparator evidence works, when it is required, how tribunals assess it, and the legal rules that govern its use in discrimination claims.

What Is Comparator Evidence?

Comparator evidence is information showing how another person (the comparator) was treated in similar circumstances.

It is used to answer a key legal question:

Would a person without the protected characteristic have been treated differently in the same situation?

Under the Equality Act 2010, this is particularly relevant in claims of:

• Direct discrimination
• Some forms of indirect discrimination
• Less favourable treatment cases

A comparator helps establish whether the treatment was genuinely discriminatory or whether it was based on legitimate business reasons.

Legal Framework for Comparator Evidence

Comparator analysis arises primarily under:

• Equality Act 2010 (direct discrimination provisions)
• Employment Tribunal case law
• Section 23 Equality Act 2010 (comparisons must be in no material difference circumstances)

Tribunals are required to compare the claimant with another person whose circumstances are not materially different, except for the protected characteristic in question.

This ensures the comparison is fair and legally valid.

Types of Comparators

1. Actual comparator

An actual comparator is a real person in the workplace who:

• Holds a similar role
• Has similar responsibilities
• Works under similar conditions
• Is treated differently

Example:
A male employee is promoted while a female employee with identical qualifications is not.

2. Hypothetical comparator

A hypothetical comparator is a legal construct used when no real comparator exists.

Tribunals ask:

How would a person without the protected characteristic have been treated in the same situation?

This is common in cases where:

• The claimant is the only person in a role
• No direct comparison exists
• The workplace is small or unique

When Comparator Evidence Is Required

Comparator evidence is most relevant in:

Direct discrimination claims

Where the claimant must show they were treated less favourably than someone in comparable circumstances.

Some harassment claims

Where treatment patterns may be assessed against others in similar roles.

Disciplinary or dismissal cases

Where consistency of treatment is examined.

However, comparator evidence is not always essential. Tribunals can still find discrimination based on:

• Inferences from evidence
• Statistical patterns
• Conduct and surrounding circumstances

What Makes a Valid Comparator?

For comparator evidence to be valid, tribunals require that circumstances are not materially different.

This typically includes:

• Same or similar job role
• Similar performance history
• Similar workplace conditions
• Same decision-maker or management structure
• Comparable conduct or behaviour

If differences are too significant, the comparator may be rejected.

The legal test focuses on substance over form, meaning tribunals assess real-world similarity rather than job titles alone.

Examples of Comparator Evidence in Practice

Pay discrimination example

A female employee alleges lower pay compared to a male colleague performing substantially similar work.

The tribunal examines:

• Job duties
• Skill level
• Responsibility
• Working conditions

If these are comparable, the male employee may serve as a valid comparator.

Promotion example

A disabled employee is not promoted, while another non-disabled employee with similar performance is promoted.

The comparator helps determine whether disability influenced the decision.

Disciplinary example

Two employees commit similar misconduct, but only one is dismissed.

Comparator evidence is used to assess consistency and potential bias.

Challenges in Using Comparator Evidence

Lack of suitable comparators

In many workplaces, no directly comparable employee exists.

Hidden differences in roles

Job titles may be similar, but responsibilities may differ significantly.

Employer control over information

Claimants may not always have access to internal data about other employees.

Subjectivity in “similar circumstances”

Tribunals must often make judgment calls about comparability.

Because of these challenges, tribunals frequently rely on broader evidence alongside comparators.

When Comparator Evidence Is Not Necessary

UK discrimination law does not always require a comparator.

Claims may succeed without one where:

• Evidence of discriminatory remarks exists
• Policies are clearly discriminatory
• Statistical evidence shows bias
• The treatment itself strongly indicates discrimination
• Harassment is established directly

The Equality Act 2010 allows tribunals to infer discrimination without strict comparator analysis where appropriate.

Hypothetical Comparator in Tribunal Analysis

When using a hypothetical comparator, tribunals consider:

• How a non-protected person would have been treated
• Whether policies would have applied differently
• Whether decision-making was influenced by bias

This approach ensures fairness where real-world comparison is not possible.

Evidence Used Alongside Comparators

Comparator evidence is rarely used in isolation. Tribunals also consider:

• Emails and written communication
• HR records and disciplinary documentation
• Witness testimony
• Workplace policies
• Statistical workforce data
• Chronology of events

Together, this creates a full evidential picture.

Employment Tribunal Process and Comparator Evidence

During a discrimination claim:

1. ACAS Early Conciliation must be completed
2. Claim is submitted to the Employment Tribunal
3. Employer provides disclosure of relevant documents
4. Both parties present comparator arguments
5. Tribunal assesses credibility and consistency

Comparator evidence often becomes central during hearings, particularly in cross-examination.

Time Limits for Claims

Comparator evidence does not affect procedural time limits, which are:

• Three months less one day from the discriminatory act

Time limits may be paused during ACAS Early Conciliation.

Remedies in Successful Claims

If comparator evidence supports a finding of discrimination, tribunals may award:

• Compensation for financial loss
• Injury to feelings damages
• Interest on awards
• In some cases, recommendations for workplace change

There is no statutory cap on discrimination compensation.

Common Questions

Do I always need a comparator to prove discrimination?

No. Comparator evidence is helpful but not always required.

Can I use someone in a different job as a comparator?

Only if their circumstances are materially similar.

What if there is no comparator at all?

A hypothetical comparator or other evidence may be used instead.

Who decides if a comparator is valid?

The Employment Tribunal determines whether circumstances are sufficiently similar.

Key Takeaways

Comparator evidence is a key tool in UK discrimination claims under the Equality Act 2010. It involves comparing how a claimant was treated against another person in similar circumstances to determine whether less favourable treatment occurred. Both actual and hypothetical comparators may be used, but they must reflect materially similar situations. While important, comparator evidence is not always required, as tribunals can rely on broader contextual evidence to establish discrimination. The assessment is highly fact-specific and plays a central role in Employment Tribunal proceedings.