This guide is maintained as a current resource for September 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.
A detailed guide to employer defences in employment tribunal claims in England and Wales, covering unfair dismissal, discrimination, objective justification, SOSR, reasonable steps defence, burden of proof, procedural compliance and practical strategies for employers facing tribunal proceedings.
Employment tribunals resolve disputes between employers and employees about alleged unlawful treatment at work. When an employee brings a tribunal claim - for example, for unfair dismissal, discrimination, victimisation, whistleblowing detriment or unlawful deductions from wages - the employer (respondent) has the opportunity to advance legal defences. These defences aim to show that the employer's conduct was lawful, justified or fall‑within recognised statutory and common law exceptions. This article explains the key defences available, how tribunals assess them, and practical considerations for both parties.
Tribunal Proceedings and Employer Defences
Employment tribunals apply specialised legislation such as the Employment Rights Act 1996 and the Equality Act 2010 when judging claims. Employees must generally file claims within three months less one day of the act complained of, following mandatory Acas Early Conciliation. Tribunals then consider factual evidence and legal arguments from both sides, assessing whether the employee's rights were breached and, if so, whether the employer can lawfully defend the claim.
Defences in Unfair Dismissal Claims
Potentially Fair Reasons for Dismissal
For an unfair dismissal claim, the employer's primary defence is to show there was a potentially fair reason for dismissal under section 98 of the Employment Rights Act 1996. Recognised fair reasons include conduct, capability, redundancy, statutory restriction, and some other substantial reason (SOSR).
An employer must prove the actual reason for dismissal was one of these categories. If successful at this stage, the tribunal then considers whether dismissal was reasonable in all the circumstances, taking into account the employer's size and resources, and whether the decision fell within the band of reasonable responses available to a reasonable employer.
Procedural Fairness
Even where a fair reason exists, an employer can defend an unfair dismissal claim by showing it followed a fair procedure. Compliance with the Acas Code of Practice on disciplinary and grievance procedures - including investigation, written communication of allegations, opportunity to respond and access to appeal - supports a defence that the employer acted reasonably. Tribunals may adjust awards if the Code was unreasonably ignored.
SOSR and “Band of Reasonable Responses”
The SOSR category is a flexible defence often invoked where no clear statutory reason fits, such as business reorganisations or an irretrievable breakdown in trust. To rely on SOSR, an employer must demonstrate:
- The principal reason for dismissal was substantial and genuine, and
- The decision to dismiss was reasonable in context.
Tribunals apply the band of reasonable responses test: a dismissal is fair if it falls within the range of outcomes that a reasonable employer might reach in similar circumstances.
Defences in Discrimination Claims
Burden and Standard of Proof
In discrimination claims under the Equality Act 2010, employees initially bear the burden of proof to show facts from which the tribunal could conclude discrimination has occurred. Once established, the burden shifts to the employer to disprove discriminatory treatment or justify it lawfully.
Objective Justification
For certain discrimination claims - particularly indirect discrimination and some cases of differential treatment linked to protected characteristics - employers may invoke objective justification. This defence requires showing that the treatment complained of was a proportionate means of achieving a legitimate aim. A legitimate aim must reflect genuine business needs, such as health and safety or operational efficiency, and the means chosen must be proportionate to achieving that aim.
This defence is not available for direct discrimination based on most protected characteristics, but may apply in specific contexts such as age discrimination and indirect discrimination.
“All Reasonable Steps” Defence (Vicarious Liability)
Where an employer is held vicariously liable for discriminatory conduct by employees or agents, there is a limited statutory defence if the employer can show it took all reasonable steps to prevent the act. This involves demonstrating effective policies, training, monitoring and enforcement designed to deter wrongful conduct. However, tribunals have emphasised that merely having policies is often insufficient without meaningful, ongoing action.
Defences in Whistleblowing and Detriment Claims
Whistleblowing claims (protected disclosures) involve allegations that an employer treated an employee detrimentally or dismissed them due to reporting wrongdoing. Under the relevant statutory framework, an employer can defend such claims by proving the dismissal or detriment was not because of the protected disclosure, or where vicarious liability is asserted (such as for a co‑worker's detrimental actions), that all reasonable steps were taken to prevent it.
Other Practical Defences and Considerations
Contradicting the Legal Elements
Employers can challenge the basic elements of a claim. For example, in unfair dismissal, they can argue no dismissal occurred, or that the employee did not meet qualifying conditions. In discrimination claims, employers can challenge causation and link to a protected characteristic.
Procedural and Evidence‑Based Defences
Presenting contemporaneous documentation, witness statements, consistent application of policies, and evidence of training and communications strengthens an employer's defence. Failure to provide required documents in disclosure may undermine the defence.
Settlement and Mitigation
Employers may also consider settlement agreements before or during tribunal proceedings, which can provide certainty and limit cost exposure. Early engagement via Acas Early Conciliation often helps resolve disputes without formal hearings.
Time Limits and Procedural Compliance
Employers must respond to tribunal claims within 28 days of service of the claim form (ET1) by lodging an ET3 form. Failure to respond timely can lead to default judgments. Body adherence to tribunal rules and deadlines is itself a practical defence against adverse procedural rulings.
Common Questions
What if an employer followed policy but the outcome was unfair?
Tribunals assess both substantive reasons and procedural fairness. Following policy helps but if a dismissal lies outside the band of reasonable responses, it may still be unfair.
Can objective justification apply to all discrimination claims?
No. It generally applies to indirect discrimination and specific limited types of less favourable treatment, rather than direct discrimination in most protected characteristics.
Is “all reasonable steps” a common defence?
It is available in limited contexts where vicarious liability is claimed. It requires well‑documented preventative measures and enforcement.
Key Takeaways
Employers defending tribunal claims must understand the legal defences specific to the type of claim. In unfair dismissal, establishing a fair statutory reason, following fair procedures and staying within the band of reasonable responses are central defences. In discrimination claims, employers may invoke objective justification or, in limited contexts, the all reasonable steps defence. Whistleblowing and detriment claims also offer particular defences. Effective defence preparation involves timely procedural compliance, careful evidence gathering, and a clear articulation of factual and legal arguments.
