Fair vs Unfair Dismissal in the UK: Employer Guide

Dismissing someone is one of the highest-risk things you’ll do as an employer - especially in a small business where roles are tight, relationships are close, and time to “get the paperwork perfect” is limited.

But the good news is this: most dismissal disputes are avoidable. If you understand what the law expects, and you follow a fair process, you can usually manage exits in a way that protects your business and treats people properly.

This guide breaks down fair vs unfair dismissal in plain English, from a small business perspective. We’ll cover what makes a dismissal “fair”, what typically makes it “unfair”, and the practical steps you can take to reduce your risk.

What Do “Fair” And “Unfair” Dismissal Mean In Practice?

In the UK, the main legal framework for unfair dismissal comes from the Employment Rights Act 1996. In simple terms:

• Unfair dismissal is when an employee is dismissed and the employer can’t show a fair reason and/or didn’t act reasonably in how they handled it.
• Fair dismissal is when you have a recognised fair reason and you follow a reasonable process, taking into account the circumstances.

Two important points that employers sometimes miss:

• It’s not just what you decide - it’s how you get there. Even if you have a “good reason”, you can still lose if the process is sloppy or inconsistent.
• Eligibility matters, but don’t rely on it. Most employees need 2 years’ continuous service to bring an ordinary unfair dismissal claim. But there are big exceptions (for example, dismissals linked to discrimination or certain protected rights can be challenged regardless of length of service).

From a business owner’s perspective, the aim is to build a dismissal decision that is:

• Legally defensible (fair reason + reasonable process)
• Commercially sensible (minimises disruption and risk)
• Human (reduces the chance of conflict escalating)

What Are The “Fair Reasons” For Dismissal?

For a dismissal to be potentially fair, you usually need to fall within one of the recognised categories. The most common fair reasons are:

• Conduct (for example, misconduct or gross misconduct)
• Capability or performance (including ill health affecting ability to do the job)
• Redundancy (role no longer needed)
• Statutory illegality or legal restriction (continuing to employ someone would break the law, or you can’t lawfully employ them in that role)
• Some other substantial reason (SOSR) (a “catch-all” category, but not a free pass)

Having a category isn’t enough on its own. The law also asks whether you acted reasonably, which is where most employers get caught out.

Conduct: Misconduct And Gross Misconduct

Conduct dismissals can range from repeated lateness to serious breaches like theft, violence, or serious confidentiality breaches.

If you’re considering dismissal for serious conduct, it’s worth being very clear on:

• what rule/policy was breached
• the evidence you have
• whether dismissal is within the “range of reasonable responses”
• whether a warning (or final warning) is more appropriate

Even where you believe it’s gross misconduct, you’ll usually want to carry out a reasonable investigation first (and for many disciplinary cases, tribunals will expect something broadly consistent with the ACAS Code). A good starting point is to work through a gross misconduct checklist so you don’t skip key steps under pressure.

Capability: Performance And Skills

Capability is often the most common issue in small businesses: someone isn’t meeting targets, can’t do key tasks independently, or isn’t suitable for the role as it’s developed.

The safest approach is to treat capability as a structured process, not a “surprise termination”. That often includes:

• clear expectations and training/support
• time to improve
• written records
• a fair meeting and chance to respond

Many businesses use a structured Performance Improvement Plan (PIP) to document expectations and milestones.

Capability: Ill Health And Long-Term Absence

Long-term sickness absence is one of the trickiest areas because it can overlap with disability discrimination risks and the duty to make reasonable adjustments.

A capability dismissal linked to health issues is sometimes fair - but only if you’ve done the work first (medical evidence, consultation, adjustments, exploring alternatives, etc.). If this is on your radar, a dedicated process for ill health capability dismissal can help you avoid making an expensive mistake.

Redundancy

Redundancy is about the role, not the person. The key risk for employers is treating redundancy like “performance management without the admin”. If you’re reducing headcount or restructuring, you’ll usually need:

• a genuine redundancy situation
• a fair selection process (if selecting between employees)
• consultation (and remember: if you’re proposing 20+ redundancies at one establishment within 90 days, collective consultation rules may apply)
• correct notice and redundancy pay where applicable

It also helps to check you’re handling notice correctly - especially if you’re juggling operational needs and employee entitlement - and the rules on redundancy notice periods are a good baseline.

SOSR (Some Other Substantial Reason)

SOSR can cover a range of scenarios (for example, a serious breakdown in working relationships, business reorganisation issues that don’t fit neat redundancy definitions, or third-party pressure).

The catch: SOSR is often where employers assume the label does the heavy lifting. It doesn’t. The process and evidence still matter, and you’ll usually need to show you explored alternatives.

What Process Should You Follow To Make A Dismissal Fair?

When it comes to fair vs unfair dismissal, process is where most claims are won or lost.

A “fair process” isn’t one single template, but most safe processes include the following stages (and you should adjust them depending on whether you’re dealing with conduct, capability, redundancy, or something else). For disciplinary and some grievance-related dismissals, the ACAS Code of Practice is also important: if a tribunal finds an unreasonable failure to follow it, compensation can be adjusted (including an uplift of up to 25%).

1) Investigate Before You Decide

For conduct issues especially, a dismissal should rarely be a first step. You’ll normally need to gather evidence, speak to relevant people, and test your assumptions.

A practical investigation usually involves:

• setting out the allegation/issue clearly
• collecting documents (emails, CCTV where lawful, logs, customer complaints)
• speaking to witnesses
• giving the employee a chance to explain

It can help to use a structured approach to workplace investigations, particularly if your team is small and it’s hard to keep things impartial.

2) Put Concerns In Writing And Invite To A Meeting

Surprises create disputes. A written invite helps show that you acted fairly and that the employee understood what was being discussed.

Your letter should usually cover:

• the issue/allegations in enough detail
• the possible outcomes (including dismissal where appropriate)
• the time/date of the meeting and who will attend
• the right to be accompanied (where applicable)

3) Hold A Fair Meeting (And Actually Listen)

The meeting shouldn’t be a box-ticking exercise. It’s your opportunity to test the evidence and hear the employee’s response (including any mitigating factors like training gaps, health issues, or misunderstandings).

Make sure you take notes and keep the tone calm and professional - even if the issue is frustrating.

4) Consider Alternatives

A key part of reasonableness is whether you considered options short of dismissal, such as:

• additional training or supervision
• adjusted duties or targets
• a written warning or final warning
• moving the employee to another suitable role (where possible)

If you’re terminating during an early-stage employment relationship, ensure your probation period process is clear and documented - it won’t remove all risk, but it often reduces disputes and confusion.

5) Make A Decision And Confirm It In Writing

Your outcome letter should set out:

• the decision and the reason
• the effective termination date
• notice arrangements (working notice vs PILON if applicable)
• final pay and holiday pay
• the right to appeal and how to do it

6) Offer An Appeal

An appeal can feel like an annoying extra step when you’re trying to keep the business running. But from a legal risk perspective, it’s important - and for disciplinary dismissals it’s part of what the ACAS Code expects. It can correct mistakes and show overall fairness.

If possible, have someone else hear the appeal - but in small businesses that’s not always realistic. If you can’t separate decision-makers, be transparent and focus on a fresh review of the evidence and process.

Common Mistakes That Turn A “Fair” Dismissal Into An Unfair One

Small businesses rarely set out to dismiss unfairly. More often, the problem is speed, emotion, or informality.

Here are some common traps that can turn an otherwise defensible decision into an unfair dismissal risk.

No Paper Trail (Or A Paper Trail That Starts Too Late)

If concerns have existed for months but nothing was documented until the week you decided to dismiss, it can look like an excuse rather than a genuine performance or conduct issue.

This is why it’s worth getting the basics right early, including having a clear Employment Contract that sets expectations and supports your policies and processes.

Inconsistent Treatment

If one employee is dismissed for an issue that others get away with, you’re much more exposed. Consistency matters, particularly with:

• lateness and attendance
• use of company equipment
• social media conduct
• sales or performance targets

If you’ve been flexible historically, consider whether that flexibility has become an expectation. (This often shows up in disputes as “but that’s how we’ve always done it”.)

Skipping Investigation Because You “Already Know What Happened”

Even if you think you have the full story, a reasonable investigation is often essential. Otherwise, you risk missing key facts (or missing how your evidence might look if challenged).

Conflating Performance With Misconduct

Some issues feel like misconduct but are actually capability. For example:

• errors due to lack of training are usually capability
• errors despite training and repeated warnings could start to look like misconduct (but you’ll still need to show the steps you took)

Choosing the wrong “track” often leads to unfairness because the process expectations differ.

Not Considering Discrimination And Protected Rights

This is a big one. Some dismissals are “automatically unfair” or can be challenged as discriminatory even without 2 years’ service.

For example, dismissals linked to pregnancy/maternity, whistleblowing, trade union activities, asserting certain statutory rights, or health issues that amount to a disability can all create serious legal exposure.

You don’t need to become an employment law specialist - but you do need to spot when there might be a protected issue in the background and slow down to get advice.

A Practical “Fair Dismissal” Checklist For Small Businesses

If you’re dealing with an exit right now (or you can see one coming), use this checklist to keep the process grounded and defensible.

Before You Start

• Check the employee’s start date (length of service can affect claim risk).
• Review the employment contract and any relevant policies (disciplinary, capability, absence, etc.).
• Be clear on the reason: conduct, capability, redundancy, illegality/legal restriction, or SOSR.

Gather Evidence

• Collect documents, communications, and records that support the issue.
• Identify witnesses and take notes of what they say.
• Keep your approach proportionate (the more serious the outcome, the more thorough you should be).

Run A Fair Process

• Put the issue in writing and invite the employee to a meeting.
• Hold the meeting, explain the concern, and let them respond.
• Consider whether adjustments, support, training, or warnings are appropriate.
• Document what you considered and why you chose your outcome.

Confirm The Outcome Properly

• Write to the employee confirming the decision and reasons.
• Deal with notice, holiday pay, and final pay carefully.
• Offer an appeal and deal with it fairly if it’s raised.

Pressure-Test The Risk

Ask yourself:

• If this ended up in a tribunal, could we explain our decision clearly with evidence?
• Have we treated this person consistently compared to others?
• Is there anything in the background (health, pregnancy, whistleblowing, grievances) that raises a protected-rights risk?

If you’re not sure, it’s usually cheaper (and far less stressful) to get advice before the dismissal rather than after.

Key Takeaways

• Most dismissal disputes come down to two things: whether you had a fair reason and whether you followed a reasonable process.
• Even if an employee can’t bring an ordinary unfair dismissal claim (for example, due to short service), you still need to watch for risks like discrimination and automatically unfair dismissal.
• For conduct dismissals, a reasonable investigation and a fair disciplinary process are often critical - especially for alleged gross misconduct (and the ACAS Code can be important).
• For performance/capability issues, you’ll usually reduce risk by using structured support steps (often including targets, training, review meetings, and written records).
• For ill-health situations, take extra care: medical evidence, consultation, and reasonable adjustments can be central to whether a dismissal is fair.
• A clear written outcome (including notice and an appeal right) helps demonstrate fairness and reduces the chance of the dispute escalating.

If you’d like help managing a dismissal fairly - or sense a situation might be heading that way - you can reach us at 08081347754 or team@sprintlaw.co.uk to discuss your options.