The Polkey Reduction — When Fair Process Wouldn't Have Changed the Outcome

Last updated: April 2026 · Content reviewed against current UK employment law

Build your employment tribunal claim — free to start, no jargon

Build your claim free

Can a Polkey reduction reduce compensation to zero?

Theoretically yes, if the tribunal finds a 100% chance dismissal would have happened immediately anyway. In practice, even strong cases see reductions of 50–80%. A 100% reduction needs near-certainty.

Does Polkey apply to discrimination cases?

No. Polkey applies only to unfair dismissal claims. In discrimination cases the focus is on injury to feelings and financial loss — there’s no Polkey-style adjustment.

What if the employer doesn’t make a Polkey argument?

If the employer doesn’t raise it, the tribunal can’t apply a Polkey reduction of its own motion. The burden is on the employer to show dismissal was inevitable.

Does Polkey apply in redundancy cases?

Yes. If procedural failures made the redundancy unfair, a Polkey reduction may apply if the employer can show the role genuinely ceased to exist and the employee would have been made redundant anyway.

What is the difference between Polkey and 100% contributory fault?

100% contributory fault wipes out compensation because the employee’s own conduct caused the dismissal. Polkey is about the employer’s hypothetical conduct — ‘we would have dismissed anyway’. Different legal frameworks, similar practical outcome.

The Polkey Reduction — When Fair Process Wouldn't Have Changed the Outcome

"Even if a dismissal was unfair because of a procedural failing, compensation may be reduced if the employer can show dismissal was inevitable."

What is the Polkey reduction?

It takes its name from the 1987 House of Lords case

Polkey v AE Dayton Services Ltd [1987] UKHL 8

. The House of Lords held that procedural failures make a dismissal unfair, but that compensation should be reduced to the extent that a fair procedure would have made no difference.

Before Polkey, employers sometimes escaped liability by arguing that a fair procedure would have been futile — the case reversed that, confirming dismissal is still unfair, but compensation is adjusted. This principle has become central to unfair dismissal law.

Ready to build your claim?

Start My Claim guides you from ET1 to hearing, step by step. Free to start, no jargon.

No credit card required · Used by claimants across the UK

How is a Polkey reduction calculated?

A Polkey reduction is expressed as a percentage (for example, 50% Polkey reduction). The tribunal considers: what would have happened if a fair procedure had been followed? Would the employee have been dismissed anyway? If so, how soon?

The reduction could also be expressed as a percentage chance. For example: if the tribunal finds there is a 70% chance dismissal would have happened anyway within three months, compensation is reduced by 70% from that three-month point forward.

Polkey reductions are not exact — the tribunal is making an estimate of what might have happened. This is inherently speculative, so tribunals apply common sense and avoid over-precision. A reduction of "around 30–50%" is more realistic than an exact figure.

Key factors in the calculation:

• Length of time before inevitable dismissal would have occurred
• Whether any alternative outcome was realistically possible (redeployment, performance improvement)
• The nature of the procedural failure and how bad it was
• The strength of the case against the employee

How to argue against a Polkey reduction

The employer bears the burden of showing dismissal was inevitable. This is a significant burden — it is not enough to say "we probably would have dismissed anyway." The employer must provide credible evidence of what would actually have happened.

Key arguments against a Polkey reduction:

• Challenge the evidence:
• Highlight inconsistencies or lack of credible evidence. If the employer's witness evidence is weak or evasive, the tribunal may not find the dismissal was inevitable.
• Realistic alternatives:
• Point to evidence that consultation, redeployment, or performance improvement were genuine, realistic possibilities. If the employer had other options, dismissal was not inevitable.
• Process failure was egregious:
• If the procedural failing was severe (e.g., no investigation at all, or complete failure to put allegations to the employee), argue that this undermines any attempt to predict what would have happened.
• Inconsistent treatment:
• Show that other employees in similar circumstances were not dismissed. This cuts against the claim that dismissal was inevitable in your case.
• Management discretion:
• Highlight that management had discretion and different managers made different decisions. This reinforces that dismissal was not automatic.

The tribunal will be alert to bare assertions by employers. If an employer says "we would definitely have dismissed" but provides no real evidence, the tribunal may reject a Polkey reduction entirely or apply only a modest one.

Polkey and contributory fault — not the same

These are two distinct concepts, and both can apply in the same case independently:

What would have happened in a fair process? This is about the employer's hypothetical conduct, not the employee's fault. A tribunal can apply a Polkey reduction even where the employee did nothing wrong.

Did the employee's own conduct contribute to their dismissal? This is about the employee's actions. If yes, compensation is reduced by a just and equitable amount — potentially to zero in extreme cases.

Example: An employee was dismissed for poor performance after a one-minute disciplinary meeting (severe procedural failing). The tribunal finds the dismissal unfair, but also finds that the employee's performance was genuinely poor and contributed to the decision. The tribunal might apply:

• A Polkey reduction (say, 40%) because a fair procedure might have resulted in redeployment or performance support
• A separate contributory fault reduction (say, 20%) because the employee's poor performance contributed

Both reductions apply independently and can compound.

Frequently Asked Questions

Theoretically yes, if the tribunal finds a 100% chance dismissal would have happened immediately anyway. In practice, this is rare. Even employers with strong cases usually see Polkey reductions of 50–80%. A 100% reduction would require near-certainty that dismissal was inevitable — a very high bar.

No. Polkey reductions apply only to unfair dismissal claims. In discrimination cases, once discrimination is proven, the focus is on compensation for injury to feelings and financial loss — there is no Polkey-style adjustment. The reasoning is that discriminatory treatment is fundamentally different from a procedurally unfair but substantively fair dismissal.

What if the employer doesn't make a Polkey argument?

If the employer fails to raise a Polkey argument, the tribunal cannot apply a Polkey reduction of its own motion. The burden is on the employer to adduce evidence that dismissal was inevitable. If they don't raise it, you are not penalised. That said, you can sometimes raise your own Polkey arguments (for instance, "even if we accept dismissal was inevitable, it would have been in six months, not immediately"), but the employer carries the main burden.

Polkey can apply in redundancy. If an employee was made redundant but the dismissal was unfair because of procedural failures (e.g., no consultation, no alternative roles offered), a Polkey reduction may apply if the employer can show the employee would have been made redundant anyway. However, the standard for "inevitability" is high — the employer must show the role genuinely ceased to exist, not merely that redundancy was foreseeable.

A 100% contributory fault reduction also wipes out compensation, but for a different reason: the employee's own conduct was solely responsible for dismissal, so no compensation is due. Polkey is about the employer's hypothetical conduct ("we would have dismissed anyway"). Contributory fault is about the employee's conduct ("your actions caused this"). The legal frameworks are distinct, though the practical outcome (no compensation) can be the same.

Build your case with confidence

Start My Claim helps you understand complex concepts like Polkey reductions and build your evidence systematically.

No credit card · Cancel any time · Used by claimants across the UK

Your claim, estimated

What could you actually be owed?

No sign-up, no card, no email. Your numbers just appear below as you type — then you decide whether to build the full case.

Polkey v AE Dayton [1987]

Employment Rights Act 1996