What is gross misconduct in UK employment law?

Gross misconduct is conduct that is so serious that it destroys the trust and confidence at the heart of the employment relationship. If genuinely established after a fair investigation and disciplinary process, it justifies immediate dismissal without notice (summary dismissal) — the employee forfeits their notice entitlement. Common examples include theft or fraud, physical violence, serious harassment or bullying, deliberate damage to property, serious breach of health and safety rules, and bringing the employer into serious disrepute.

Despite the severity of the conduct, employers must still follow a fair dismissal procedure before dismissing for gross misconduct. This means investigating the allegations, inviting the employee to a disciplinary hearing, allowing them to bring a colleague or union rep, considering their response, and offering a right of appeal. Failure to follow this process can make an otherwise fair dismissal unfair — ACAS uplift can add up to 25% to any Tribunal award.

Not all serious conduct amounts to gross misconduct — the label depends on the contract, the employee handbook, and the specific circumstances. Where the same conduct would not result in dismissal for other employees (inconsistent treatment), a dismissal for gross misconduct can still be unfair.