What is unfair dismissal? A plain-English guide

Being dismissed is disorientating, and the word "unfair" does a lot of work in ordinary conversation that it does not do in law. A dismissal can feel deeply unfair and still be lawful. It can also look tidy on paper and still be unfair in the legal sense, because of how it was handled. This guide explains what unfair dismissal actually means, who can bring a claim, the deadline that catches most people out, and what a tribunal can award.

What unfair dismissal means in law

Unfair dismissal is a statutory right under the Employment Rights Act 1996. If you qualify, your employer must show two things.

First, that the dismissal was for one of five potentially fair reasons: conduct, capability or qualifications, redundancy, a legal restriction that makes continued employment unlawful, or "some other substantial reason" of a kind that justifies dismissal.

Second, that dismissing you for that reason was reasonable in the circumstances, including whether a fair procedure was followed. This second limb is where most claims are won and lost. An employer can have a genuine reason and still lose because it skipped the investigation, denied the right to be accompanied, or made the decision before hearing the answer.

Who can claim

• You must be an employee, not self-employed or a genuine contractor. Job title matters far less than how you actually work.
• You normally need two years' continuous service at the date the dismissal takes effect. This qualifying period is due to be removed under the Employment Rights Act 2025 reforms, so check where you stand at the time of your dismissal rather than relying on what someone told you last year.
• There is no minimum service at all where the reason for dismissal is automatically unfair.

Automatically unfair reasons

Some reasons for dismissal are unfair regardless of process and regardless of length of service. The most common are pregnancy and maternity, taking family leave, whistleblowing (making a protected disclosure), asserting a statutory right such as the minimum wage or paid holiday, trade union membership or activities, and raising health and safety concerns.

If any of these are in play, your position is much stronger than the two-year rule suggests, and compensation for whistleblowing and discrimination is not capped in the same way. This is the single most common thing people miss when they assume they have no claim.

The three-month deadline

You normally have three months less one day from the effective date of termination to start your claim. Before you can lodge it you must notify ACAS and go through early conciliation, which pauses the clock while it runs.

Tribunals are strict about this. Extensions are possible but rare, and "I was waiting to hear back from HR" or "I was appealing internally" is not usually enough. Starting ACAS early conciliation costs nothing and does not commit you to a claim, so if you are anywhere near the deadline, do it and take advice afterwards rather than the other way round.

What a fair process looks like

For a conduct dismissal, a reasonable employer would generally investigate before deciding, put the allegations to you in writing, hold a meeting at which you can respond, allow you to be accompanied by a colleague or union representative, take the decision by someone who has not already made up their mind, and offer an appeal to a different decision-maker.

Redundancy adds its own requirements: a genuine redundancy situation, a fair and objectively applied selection pool and criteria, meaningful individual consultation, and a proper search for suitable alternative employment. Collective consultation obligations apply where 20 or more redundancies are proposed at one establishment within 90 days.

Where the employer unreasonably fails to follow the ACAS Code of Practice on disciplinary and grievance procedures, a tribunal can increase compensation by up to 25%.

What you can recover

Compensation for unfair dismissal has two parts.

• Basic award. Calculated from your age, gross weekly pay and years of service, subject to a statutory weekly pay cap that is reviewed each April. It mirrors the statutory redundancy payment calculation.
• Compensatory award. Your actual financial loss, mainly lost earnings, pension and benefits from dismissal until you are back on equivalent pay. It is capped at the lower of 52 weeks' gross pay or the annual statutory limit, which also changes each April. That cap does not apply to whistleblowing or discrimination claims.

Awards can be reduced. If the tribunal finds you would probably have been dismissed anyway had a fair process been followed, it can cut the compensatory award to reflect that chance, sometimes to nothing. Contributory fault can reduce it further. You are also expected to mitigate your loss by looking for other work and keeping evidence that you did.

Reinstatement and re-engagement exist as remedies but are ordered rarely. In practice most cases are about money and about getting a clean reference and a line drawn.

What actually helps your case

Cases are reconstructed months later from documents, so the documents decide them. Before you lose access to your work systems, keep copies of your contract, any policies you were disciplined under, the invitation and outcome letters, meeting notes, appraisals and your payslips. Written records made at the time carry far more weight than what you remember later.

Be careful with what you take. Copying confidential company material or client data can hand your employer a genuine grievance of its own and can damage an otherwise good claim. Take what relates to you and your treatment, and get advice if you are unsure.

Where a specialist changes the outcome

Three things move the number. Whether the claim is characterised properly at the outset, because an ordinary unfair dismissal claim and a whistleblowing or discrimination claim are worth very different amounts. Whether the loss is calculated properly, including pension and benefits, which is where employers routinely open low. And timing, because the same case settles for more before the employer has spent money on lawyers and before you have been out of work long enough to look like you are settling from weakness.

If you have been dismissed, or you are being pushed towards resigning, the useful step is a short conversation with a specialist employment solicitor while the deadline is still comfortably ahead of you.