This article applies to England, Wales and Scotland.
In brief: There is no legal list of "sackable offences" in UK employment law. Whether conduct justifies dismissal depends on its seriousness, your employer's policies, and whether a fair process was followed. Gross misconduct can justify instant dismissal for a first offence, while ordinary misconduct typically requires warnings first. Your employer must still investigate and hold a hearing before dismissing you.
Last updated: March 2026
By Yerty | This guide was created using analysis of tribunal cases and official ACAS/Gov.uk guidance.
You've done something wrong at work, or you've been accused of it, and now you're wondering: can I actually be sacked for this? The answer is rarely black and white. UK employment law does not have a fixed list of offences that automatically lead to dismissal. What counts as a sackable offence depends on the severity of the conduct, your employer's own policies, and the circumstances. This guide explains how it works.
Important: This guide provides information about UK employment law. It is not legal advice. Yerty is not a law firm. Every situation is different. If you're facing disciplinary action, consider speaking to a solicitor for advice specific to your circumstances.
Why There Is No Official "Sackable Offences List"
Neither the Employment Rights Act 1996 nor the ACAS Code of Practice provides a definitive list of offences that justify dismissal. The reason is that context matters too much for a fixed list to work fairly.
The same behaviour could be treated as ordinary misconduct in one workplace and gross misconduct in another, depending on the role, the industry, and the potential consequences. Sending a personal email from a work computer might merit a quiet word in one company and a disciplinary investigation in another.
What the law does say is that "conduct" is one of the five potentially fair reasons for dismissal under section 98 of the Employment Rights Act 1996. But calling something a conduct dismissal does not make it automatically fair. A tribunal will examine whether the employer acted reasonably in treating the conduct as sufficient grounds for dismissal.
The Difference Between Misconduct and Gross Misconduct
This distinction determines how your employer is expected to respond:
| Type | What it means | Expected response |
|---|---|---|
| Ordinary misconduct | A breach of workplace rules that is not severe enough to destroy trust | Verbal or written warnings, escalating with repeated offences |
| Serious misconduct | A more significant breach, but still short of gross misconduct | Formal disciplinary process, potentially a final written warning |
| Gross misconduct | Conduct so serious it fundamentally breaks the employment relationship | Can justify summary dismissal (without notice) for a first offence |
Most employers set out what they consider gross misconduct in their disciplinary policy or staff handbook. If your employer has not defined it clearly, that can make it harder for them to justify dismissal at a tribunal.
Common Examples of Conduct That May Justify Dismissal
While there is no statutory list, the following are widely recognised across UK workplaces as potentially justifying dismissal. Whether dismissal is actually fair depends on the specific facts and the process followed.
Typically treated as gross misconduct:
- Theft, fraud, or deliberate falsification of records
- Physical violence or credible threats of violence
- Serious bullying, harassment, or discrimination
- Being under the influence of drugs or alcohol at work (particularly in safety-critical roles)
- Serious breaches of health and safety rules
- Gross insubordination or refusal to follow a lawful instruction
- Serious breach of confidentiality or data protection
- Criminal conduct connected to your employment
Typically treated as ordinary or serious misconduct:
- Persistent lateness or unauthorised absence
- Minor breaches of workplace rules
- Poor timekeeping
- Inappropriate language or behaviour that falls short of harassment
- Misuse of company equipment for personal purposes
- Failure to follow reasonable management instructions
The line between categories is not always obvious. Your employer's handbook should give examples, but a tribunal will look at whether the decision to dismiss was within the "band of reasonable responses" open to a reasonable employer.
What Makes a Dismissal Fair?
Under the Employment Rights Act 1996, a dismissal for conduct is only fair if the employer can show two things:
1. A genuine and reasonable belief in the misconduct
Your employer does not need to prove you committed the offence beyond reasonable doubt. They need to show they had a genuine belief in your guilt, based on reasonable grounds, following a reasonable investigation. This is known as the Burchell test (from the case British Home Stores v Burchell).
2. A fair and reasonable procedure
The ACAS Code of Practice requires employers to investigate properly, inform you of the allegations in writing, hold a disciplinary hearing, allow you to be accompanied, and offer a right of appeal. Skipping steps can make a dismissal procedurally unfair even where the conduct was serious.
3. A proportionate response
Dismissal must fall within the range of reasonable responses. If a reasonable employer could have given a warning instead of dismissing, the decision may be found to be unfair. Factors include your length of service, disciplinary record, any mitigating circumstances, and how similar cases have been handled in the past.
Consistency Matters
One of the most common reasons tribunals find a dismissal unfair is inconsistent treatment. If a colleague committed similar conduct and received a warning while you were dismissed, your employer will need to explain the difference convincingly.
Employers should apply their disciplinary policies consistently. If they don't, that creates an argument that the decision to dismiss you was unreasonable, regardless of whether the conduct itself was serious.
Your Rights During a Disciplinary Process
Whatever the allegation, you have rights throughout the disciplinary process:
- To know the allegation in writing, with enough detail to prepare a response
- To see the evidence your employer has gathered before the hearing
- To attend a hearing and present your side
- To be accompanied by a colleague or trade union representative (a statutory right under the Employment Relations Act 1999)
- To have mitigating circumstances considered before a decision is made
- To appeal the outcome
If any of these steps are missing, the dismissal may be unfair even if the conduct was genuine. For more on how this plays out in practice, see our guide on gross misconduct and first offences.
Frequently Asked Questions
Is there a legal list of sackable offences in the UK?
No. Neither the Employment Rights Act 1996 nor the ACAS Code provides a statutory list. Your employer may define gross misconduct in their handbook or disciplinary policy, but a tribunal will assess each case on its facts.
Can I be sacked without a warning?
For gross misconduct, yes. Your employer can dismiss you without prior warnings if the conduct is serious enough. But they must still follow a fair process: investigate, hold a hearing, consider mitigation, and offer an appeal. For ordinary misconduct, warnings are expected before dismissal.
What counts as gross misconduct?
Conduct that fundamentally breaks the trust between employer and employee. Common examples include theft, violence, serious harassment, and major safety breaches. There is no fixed legal definition; it depends on the circumstances and your employer's policy.
Can I be dismissed for something that happened outside work?
Potentially, if the conduct affects your ability to do your job, damages your employer's reputation, or breaks the relationship of trust. But your employer cannot simply rely on the fact that something happened. They must still investigate and follow a fair process.
What if my employer's handbook doesn't mention the offence?
The absence of the offence from your employer's policies does not prevent dismissal, but it makes it harder for your employer to justify. If you had no reason to know the conduct was considered a sackable offence, a tribunal may find the dismissal unfair.
How long do I have to challenge a dismissal?
The time limit is 3 months minus 1 day from your effective termination date. You must start ACAS early conciliation before submitting a tribunal claim. For unfair dismissal, you currently need at least 2 years' service.
Sources
- Employment Rights Act 1996, s.98 (fair reasons for dismissal) — https://www.legislation.gov.uk/ukpga/1996/18/section/98
- ACAS Code of Practice on Disciplinary and Grievance Procedures — https://www.acas.org.uk/acas-code-of-practice-on-disciplinary-and-grievance-procedures
- "Types of dismissal", ACAS — https://www.acas.org.uk/dismissals/types-of-dismissal
- British Home Stores v Burchell [1980] ICR 303 — the test for reasonable belief in misconduct
- Employment Relations Act 1999, s.10 — right to be accompanied