Few phrases carry as much weight in a workplace as “gross misconduct”. For an employer, it usually comes upwhen something serious has happened and there is pressure to act quickly.
For an employee, being told that their conduct could amount to gross misconduct can be a pretty dauntingexperience.
Gross misconduct is serious because it can justify immediate dismissal without notice. But that does not mean that calling something “gross misconduct” automatically makes dismissal the right or lawful outcome.
This is where employers can get caught out. The label itself is not what protects a business. What matters is having a fair process, properly considering the circumstances and being able to show why the decision to dismiss was reasonable.
With the Employment Rights Act 2025 reducing the required service for unfair dismissal claims from the current two years to six months from January 2027, getting this right matters more than ever. Here is what employers, HR teams and employees need to understand.
What is gross misconduct?
Gross misconduct is behaviour that is so serious, or that has such serious effects, that it may fundamentally damage the employment relationship.
The practical difference is one of degree. Ordinary misconduct, such as persistent lateness or unauthorised absence, would normally be dealt with through warnings and a genuine opportunity to improve. Gross misconduct, by contrast, is conduct that is serious enough that the employer may be unable to continue the employment relationship.
Importantly, gross misconduct is generally concerned with a single act that is sufficiently serious to justify dismissal without notice. A series of misconduct issues does not become gross misconduct simply because they have accumulated over time.
Where an employer dismisses without notice on that basis, it is known in law as summary dismissal. In plain English, that means the employment relationship ends immediately, without notice (or payment of notice). It does not, however, mean that the employee loses everything they are owed. Any accrued but unpaid wages and holiday pay would still usually need to be paid.
What actually counts as gross misconduct?
There is no statutory list. UK legislation does not define gross misconduct anywhere, which means there is no single definitive list of conduct that will amount to gross misconduct. Each case will need to be considered on its own facts.
Having said that, both Acas and GOV.UK point to the same familiar examples, including:
- theft and fraud
- physical violence
- gross negligence, meaning a serious lack of care towards duties or towards other people
- serious insubordination, such as refusing to follow a reasonable and lawful instruction
These examples are not exhaustive. Employers may also include sector-specific or company-specific examples in a disciplinary policy or staff handbook. These commonly cover serious health and safety breaches, incapacity at work through drugs or alcohol, deliberate damage to company property, bullying and harassment, and serious misuse of confidential information.
In addition, context matters enormously. The same behaviour may justify dismissal in a safety critical role and fall well short of it elsewhere. Seniority, regulatory duties, safeguarding obligations and the level of risk created all feed into the assessment. A handbook is the starting point for that conversation, not the end of it.
Does gross misconduct always mean dismissal?
No, and this is one of the most common misunderstandings we see.
Even where the conduct is proven, an employer still has to decide whether dismissal is a proportionate response. A tribunal will not ask what it would have done if it were in the employer’s position. It will consider whether dismissal fell within the range of reasonable responses open to a reasonable employer, taking into account the seriousness of the conduct, the employee’s length of service, any mitigating factors and whether trust can realistically be rebuilt.
As a result, alternatives such as a final written warning, redeployment (where appropriate) or additional training may sometimes be both the fairer and the safer outcome.
It is important that employers can demonstrate that they have genuinely considered alternatives before deciding to dismiss. If an alternative is considered but ultimately rejected, the employer should also explain in the outcome why it was not considered appropriate in the circumstances. This creates a clear record of the decision-making process and can be important evidence if the dismissal is later challenged as unfair.
The key point is not that an employer must always choose an alternative to dismissal, but that it should be able to show that it properly considered whether there was a reasonable alternative and why dismissal was ultimately considered appropriate.
Following a fair procedure
Immediate dismissal does not mean instant dismissal. Even in cases that look clear cut, employers should follow the Acas Code of Practice on disciplinary and grievance procedures. In broad terms, that means:
- Investigate promptly and proportionately: Establish the facts as far as is reasonably practicable, gather the relevant evidence and interview witnesses separately.
- Think carefully about suspension: Suspension on full pay may be appropriate where there are safety or evidence concerns, but it should be a neutral holding step and never a punishment in itself.
- Put the allegations in writing: Tell the employee clearly what they are accused of, confirm that gross misconduct is being considered, and provide sufficient information about the allegations and evidence to allow them to properly prepare for the hearing.Hold a fair hearing: The employee has a statutory right to be accompanied by a colleague or trade union representative (should they wish), and a genuine opportunity to respond to the allegations against them and raise mitigation.
- Decide and explain: Wherever possible, the hearing should be chaired by someone who did not lead the investigation. Confirm the outcome in writing, with clear reasons for the decision and, where dismissal is being considered, why that sanction was considered appropriate.
- Offer an appeal: heard by someone who has not been involved in the case up to that point. The appeal should provide a genuine opportunity to challenge the decision and should be considered with an open mind, rather than being treated as a formality.
Skipping these steps is expensive. Where an employer unreasonably fails to follow the Acas Code, an employment tribunal can increase compensation by up to 25 percent.
Why the stakes are rising
The Employment Rights Act 2025 is changing dismissal law substantially, and three developments in particular should be on every employer’s radar.
From 1 October 2026, the time limit for bringing most employment tribunal claims will increase from three months to six months, giving employees far longer to decide whether to challenge a decision.
Then, for dismissals from 1 January 2027, the qualifying period for bringing an ordinary unfair dismissal claim will be reduced from two years to six months. At the same time, the statutory cap on the compensatory award for unfair dismissal will be removed.
Taken together, that means a much larger group of employees will be able to bring an unfair dismissal claim, they will have longer to do so, and the potential compensation will no longer be subject to the current statutory cap. In short, a rushed or poorly documented gross misconduct dismissal will carry more risk than at any point in recent memory.
Now is the moment to review your policies and processes rather than wait. We are tracking each stage of the Act as it comes into force on the Thrive blog.
Common pitfalls to avoid
- Treating the wording in your handbook as the conclusion rather than the starting point.
- Reaching a decision before the disciplinary hearing has taken place.
- Failing to share the relevant evidence and information with the employee in advance.
- Treating comparable cases inconsistently without a clear and recorded justification.
- Using suspension as a sanction, or leaving someone suspended with no explanation or clear review point.
- Weak record keeping. Tribunals look very closely at documentation, and sparse notes can make it much harder to demonstrate that the employer acted reasonably and followed a fair process.
What should you do next?
Gross misconduct cases are rarely about the label. They turn on evidence, proportionality and process. A fair and well documented approach protects your people, your culture and your business, and it is considerably cheaperthan defending a claim.
If you are reviewing your policies ahead of the 2027 changes, our disciplinary and performance management page sets out how we support employers day to day.
You will find more practical guidance across the rest of our blog, and if you would rather watch than read, our founder Jodie Hill share practical employment law guidance, including on neurodiversity and workplace best practice on our YouTube channel.
Whether you are an employer facing a difficult situation, an HR professional getting your processes in order, or an employee who is unsure where you stand, get in touch to discuss how we can help. You can contact us at enquiries@thrivelaw.co.uk or call us on 0113 869 8101.
