What counts as gross misconduct under UK employment law?

Gross misconduct is conduct so serious that it fundamentally breaches the employment relationship, justifying immediate dismissal without notice (summary dismissal). The key test is whether a reasonable employer could have treated the conduct as gross misconduct — not whether you, personally, would have done so.

Common examples of gross misconduct

UK employment tribunals consistently uphold the following as capable of being gross misconduct:

• Theft or fraud — including expense fraud, time fraud (e.g. falsifying timesheets), misappropriation of company property.
• Physical violence or assault in the workplace or in a work-related context.
• Serious health and safety breaches — particularly where harm or risk of harm to others is created.
• Serious breach of confidence — leaking commercial-in-confidence data, breaching client confidentiality.
• Unfit for work due to alcohol or drugs (subject to disability considerations and any addiction-as-disability case).
• Bullying, harassment, or discrimination — especially where there is a clear protected-characteristic dimension.
• Serious misuse of company IT systems — accessing pornography, attempting unauthorised access, large-scale data exfiltration.
• Bringing the company into serious disrepute through public conduct.
• Wilful insubordination — refusing a lawful and reasonable instruction in a manner that amounts to a fundamental breach.

What your policy must do

Your disciplinary policy should:

• List examples of conduct that may amount to gross misconduct (not an exhaustive list — the law allows for case-specific judgement).
• Make clear that gross misconduct may result in summary dismissal.
• Confirm that the disciplinary procedure still applies — there is no "skip the process" exception for gross misconduct.

The process still applies — always

Even for the clearest case of gross misconduct, the employer must follow the ACAS Code:

1. Investigate.
2. Invite to a hearing in writing.
3. Hold the hearing with the right to be accompanied.
4. Decide and write to the employee.
5. Offer the right of appeal.

You may suspend the employee on full pay while you investigate — that is not a disciplinary sanction in itself. Suspension should be a precaution, not a punishment, and should be as short as possible.

ERA 2025 implications

From 1 January 2027, two changes make procedural failings more expensive:

• The unfair dismissal qualifying period drops from two years to six months.
• The compensation cap is abolished — tribunals can award unlimited compensation.

A gross misconduct dismissal that follows the right outcome but with a flawed procedure can still be unfair dismissal. The procedure matters as much as the underlying facts.

Common pitfalls

• Treating gross misconduct as a shortcut. It is not — you still need an investigation and a hearing.
• Pre-judging the outcome. The investigator should not be the decision-maker.
• No right of appeal. This alone can render the dismissal unfair.
• Inconsistent application. If you didn't dismiss someone for similar conduct previously, you'll need to explain why this case is different.