Gross Misconduct: How to Dismiss Fairly and Avoid a Tribunal

An employee steals from the till, assaults a colleague, or leaks confidential client data. You know it is gross misconduct. You want them gone. The temptation is to march them out the door immediately.

Do not do that.

Even when the misconduct is obvious, dismissing without following a fair process is one of the fastest ways to lose an unfair dismissal claim. Tribunals do not just ask whether the employee did the thing. They ask whether you handled it properly.

This guide covers what counts as gross misconduct under UK employment law, the correct process for a gross misconduct dismissal as a UK employer, and the mistakes that regularly turn a strong case into a losing one.

Last updated: April 2026

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What Counts as Gross Misconduct for UK Employers

Gross misconduct is conduct so serious that it fundamentally destroys the employment relationship. It justifies summary dismissal: dismissal without notice and without payment in lieu of notice.

There is no statutory list of gross misconduct. What qualifies depends on the circumstances, the employee's role, and your workplace. But the ACAS Code of Practice on Disciplinary and Grievance Procedures and established case law give a clear framework.

Common Gross Misconduct Examples for UK Employers

The following are widely recognised as gross misconduct across most workplaces:

• Theft, fraud, or serious dishonesty. Taking company property, falsifying expenses, submitting fraudulent timesheets, or lying about qualifications.
• Physical violence or threats of violence. Assaulting a colleague, customer, or anyone at work. Threatening behaviour that makes others fear for their safety.
• Sexual harassment or serious harassment. Unwanted sexual conduct, discriminatory harassment, or bullying so severe it amounts to gross misconduct. From April 2026, sexual harassment is now a qualifying whistleblowing disclosure under the Employment Rights Act 2025.
• Serious insubordination. A deliberate and wilful refusal to follow a reasonable and lawful management instruction, where the refusal undermines the employment relationship entirely.
• Being under the influence of drugs or alcohol at work. Particularly in safety-critical roles, but applicable in any workplace where it creates risk or breaches policy.
• Deliberate damage to company property. Intentional destruction or sabotage of equipment, systems, or premises.
• Serious breach of confidentiality. Sharing trade secrets, client data, or commercially sensitive information without authorisation.
• Gross negligence. A single act of negligence so serious that it causes or risks significant harm. Not just carelessness, but recklessness.
• Bringing the organisation into serious disrepute. Conduct outside work so serious it damages the employer's reputation or makes continued employment untenable.

Your Disciplinary Policy Must Define Gross Misconduct

Your employee handbook should contain a non-exhaustive list of gross misconduct examples specific to your workplace. A hospital will have different categories than a marketing agency.

If your policy does not list examples, a tribunal may still find dismissal was fair if the conduct was obviously serious. But having a clear policy strengthens your position significantly.

The list should be explicitly non-exhaustive. Use wording like "the following are examples of gross misconduct, but this list is not exhaustive." This preserves your ability to treat unlisted conduct as gross misconduct where circumstances warrant it.

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The Correct Process: How to Dismiss for Gross Misconduct in the UK

Getting the substance right is not enough. You must also get the process right. The Employment Rights Act 1996 (s.98) requires that a dismissal be fair in both the reason and the procedure. The ACAS Code of Practice on Disciplinary and Grievance Procedures sets the procedural benchmark.

A tribunal will ask three questions (the test from British Home Stores v Burchell [1978]):

1. Did the employer genuinely believe the employee was guilty of misconduct?
2. Did the employer have reasonable grounds for that belief?
3. Had the employer carried out as much investigation as was reasonable in the circumstances?

If you fail on any of those three, the dismissal is likely to be unfair regardless of what the employee actually did.

Step 1: Suspend (If Necessary)

Suspension is not a punishment. It is a neutral act to allow a proper investigation. Only suspend where there is a genuine reason: risk to the investigation, risk to other employees, or risk to the business.

Suspension should be on full pay. Unpaid suspension without a clear contractual right risks a breach of contract claim. Keep it as short as possible. Write to the employee confirming the suspension, the reason, the expected duration, and any conditions.

Step 2: Investigate Thoroughly

The investigation is where most employers lose their case. A rushed or superficial investigation is the single most common reason gross misconduct dismissals are overturned at tribunal.

What a reasonable investigation looks like:

• Appoint an investigator who is not the decision-maker. Ideally someone who has not already formed a view on the outcome.
• Gather evidence. Interview witnesses, collect documents, review CCTV, check system logs, preserve emails.
• Interview the employee. Give them a chance to explain. Do not go in assuming guilt. If they raise points that need checking, check them.
• Document everything. Write up witness statements, keep copies of evidence, create a timeline. If it is not written down, it did not happen.
• Produce an investigation report. Summarise the findings and whether there is a case to answer.

The depth of investigation should be proportionate to the seriousness of the allegation. A caught-on-camera theft may need less investigation than complex financial fraud. But even clear-cut cases need some process.

For detailed guidance on running the full disciplinary process, see our disciplinary procedure employer guide.

Step 3: Invite to a Disciplinary Hearing

Once the investigation concludes there is a case to answer, write to the employee. The invitation letter must include:

• The specific allegations in detail
• Confirmation that dismissal is a possible outcome
• Copies of all evidence you intend to rely on
• The date, time, and location of the hearing
• Their right to be accompanied by a trade union representative or work colleague

Give reasonable notice. ACAS does not specify an exact timeframe, but five working days is common and widely considered reasonable.

Step 4: Hold the Hearing

The hearing must be conducted by someone with authority to dismiss who has not been involved in the investigation. In smaller businesses where this separation is difficult, document why and show you took steps to ensure objectivity.

At the hearing:

• Present the allegations and evidence
• Allow the employee to respond fully
• Allow their companion to participate
• Consider mitigating factors: length of service, disciplinary record, personal circumstances
• Adjourn to consider the evidence before deciding

Step 5: Make the Decision

Consider everything: the evidence, the employee's explanation, mitigating factors, consistency with how you have treated similar cases, and their disciplinary record.

If you conclude gross misconduct occurred and dismissal is within the range of reasonable responses, you can dismiss summarily. Write to the employee confirming the decision, the reasons, and their right to appeal.

Step 6: Offer a Right of Appeal

The right of appeal is not optional. A dismissal without it is almost guaranteed to be found procedurally unfair.

The appeal should be heard by someone more senior not involved in the original decision. The appeal can uphold the dismissal, overturn it, or substitute a lesser sanction.

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Common Mistakes That Lose Tribunal Cases

Skipping or Rushing the Investigation

Even with CCTV footage of the employee stealing, you still need to investigate, hold a hearing, and let them explain. The footage might have context you are unaware of.

Treating Summary Dismissal as Instant Dismissal

Summary dismissal means without notice. It does not mean without process. You can take days or weeks to investigate before summarily dismissing. The "summary" part is about the notice period, not the speed of the decision.

Inconsistency

If you dismissed Employee A for fighting but gave Employee B a final warning for the same thing, you need a good reason for the difference. Inconsistency is one of the strongest arguments an employee can make at tribunal.

Not Letting the Employee Explain

A common pattern: the employer "knows" what happened, calls the employee in, and treats the hearing as a formality. This is procedurally unfair even if the employer was right about the facts.

Failing to Consider Alternatives

Dismissal for gross misconduct does not have to be automatic. A tribunal expects you to consider whether a lesser sanction might have been appropriate. You can still decide only dismissal is appropriate, but you need to show you considered it.

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Gross Misconduct and the Employment Rights Act 2025

The Employment Rights Act 2025 makes several changes that affect gross misconduct dismissals for UK employers.

Day One Unfair Dismissal Rights (January 2027)

From January 2027, the qualifying period for ordinary unfair dismissal drops from two years to six months. Employees you hire now will have unfair dismissal rights much sooner. Getting your gross misconduct process right is no longer something you can defer for new starters.

For full details, see our guide to day one unfair dismissal rights.

Sexual Harassment as Whistleblowing (April 2026)

From April 2026, disclosures about sexual harassment are qualifying whistleblowing disclosures. If an employee reports sexual harassment and you then dismiss them for gross misconduct, you need to be certain the dismissal is genuinely about the misconduct and not connected to the disclosure. Automatic unfair dismissal for whistleblowing has no compensation cap.

Probationary Periods

The ERA 2025 changes how probationary periods interact with unfair dismissal. See our probationary periods guide for the updated position.

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Settlement Agreements: When to Consider One

Sometimes, even with a strong case, a settlement agreement is the pragmatic choice. The employee might have a procedural argument. The cost of a tribunal may exceed what a settlement would cost. Or the allegations are sensitive and you want confidentiality.

A settlement agreement is a legally binding contract where the employee waives their right to bring tribunal claims in exchange for a financial payment and agreed terms. The employee must receive independent legal advice for the agreement to be valid.

Our settlement agreement employer guide covers the full process.

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FAQ: Gross Misconduct Dismissal

Q: Can I dismiss an employee on the spot for gross misconduct?

A: No. Even in the clearest cases, you must follow a fair process: investigate, invite to a hearing, hear their side, then decide. Summary dismissal means without notice pay, not without procedure. Skipping the process is the most reliable way to lose at tribunal, even when the employee clearly did it.

Q: Does the employee get paid during suspension for gross misconduct?

A: Yes. Suspension pending investigation should be on full pay unless your contract explicitly allows unpaid suspension (rare, and risky even then). Suspension is a neutral act, not a punishment. Withholding pay can amount to breach of contract and will undermine your position at tribunal.

Q: What if the employee resigns before I can dismiss them?

A: An employee can resign at any time. If they resign during a disciplinary process, you can still complete the process and record the outcome on file. You are not obliged to withdraw the allegations. Some employers note on references that the employee "resigned during a disciplinary process." Be factual and avoid anything that could be challenged as defamatory.

Q: Can an employee claim unfair dismissal for gross misconduct with less than two years' service?

A: Under current rules, employees with less than two years' service generally cannot claim ordinary unfair dismissal. From January 2027, this drops to six months under the Employment Rights Act 2025. Even now, employees with any length of service can claim automatically unfair dismissal (discrimination, whistleblowing, asserting a statutory right). Never assume short service makes you safe.

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Get Your Disciplinary Procedure Checked

Is your disciplinary procedure up to date for ERA 2025? The EmployerKit Audit checks your handbook and policies against current requirements. From £49. Visit employerkit.com/tools/employerkit-audit.

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Last updated: April 2026