How to Run a Fair Disciplinary Procedure: The UK Employer Guide

Getting a disciplinary procedure wrong is expensive. A tribunal can award an uplift of up to 25% on compensation where an employer has unreasonably failed to follow the ACAS Code of Practice on Disciplinary and Grievance Procedures.

From January 2027, the unfair dismissal qualifying period drops to six months. Employees you hire from July 2026 onwards will have unfair dismissal rights earlier. That means your disciplinary process needs to be sound for new employees much sooner than before.

This guide walks you through the full process, from the initial allegation through to appeal.

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The ACAS Code of Practice

The ACAS Code of Practice on Disciplinary and Grievance Procedures sets the standard for a fair disciplinary process in the UK. Employment tribunals must take it into account when deciding whether an employer acted reasonably.

You do not have to follow the ACAS Code word for word. But if you deviate significantly from it without good reason, you risk a finding of unfair dismissal and a 25% uplift on any compensation award.

The ACAS Code is publicly available at acas.org.uk and is free to read. Your disciplinary policy should align with it.

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When to Use a Disciplinary Process

A disciplinary process is used when an employee's conduct or performance is causing problems that need to be formally addressed.

Conduct issues include:

• Persistent lateness or unexplained absence
• Failure to follow reasonable management instructions
• Insubordination or disrespectful behaviour
• Minor dishonesty (falsifying records, minor expenses fraud)
• Use of company systems for personal use contrary to policy
• Behaviour outside work that affects the employment (for example, criminal activity that makes continued employment untenable)

Gross misconduct is conduct so serious that it justifies dismissal without notice (summary dismissal). Examples include:

• Theft, fraud, or serious dishonesty
• Physical assault or threatening behaviour
• Sexual harassment
• Being under the influence of drugs or alcohol at work
• Deliberate damage to company property
• Serious breach of confidentiality

Your disciplinary policy should list examples of gross misconduct specific to your workplace. What is gross misconduct in one sector may be different from another.

Capability (performance) issues are addressed through the same ACAS Code process, though the detail differs. Performance management is not about blame: it is about identifying why someone is not meeting expectations and whether support, training, or a different role could resolve the issue.

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The Disciplinary Process: Step by Step

Step 1: Carry Out an Investigation

Before any formal action, carry out a reasonable investigation. The extent of the investigation should be proportionate to the allegation.

For a minor misconduct issue: a brief review of the facts, a conversation with the employee and relevant colleagues, and a short written summary may be sufficient.

For a more serious allegation: a fuller investigation involving interviews, document reviews, and potentially an independent investigating officer is appropriate.

The investigation should:

• Establish the facts (what happened, when, who was involved)
• Gather evidence (emails, witness statements, CCTV, system logs)
• Be conducted promptly (delays damage credibility)
• Be objective (do not pre-judge the outcome)

Suspension: You can suspend an employee on full pay while investigating a serious allegation. Suspension is not a punishment and should not be used as one. It should only be used where continued presence at work would hinder the investigation, risk harm, or put the employee or colleagues at risk. Keep suspension as brief as possible.

Document the investigation in writing.

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Step 2: Invite the Employee to a Disciplinary Hearing

Once the investigation is complete and you have decided there is a case to answer, invite the employee to a formal disciplinary hearing in writing.

The invitation letter should:

• State that this is a formal disciplinary hearing
• Set out the specific allegation(s)
• Include or attach the evidence you intend to refer to
• State the date, time, and location of the hearing
• Inform the employee of their right to be accompanied by a colleague or trade union representative
• Give sufficient notice (typically five working days minimum, but ACAS recommends as much reasonable notice as possible)

Right to be accompanied: Under the Employment Relations Act 1999, employees have a statutory right to be accompanied at any formal disciplinary or grievance hearing. The companion can be:

• A work colleague
• A trade union representative (whether or not the union is recognised)

They can address the hearing and confer with the employee but cannot answer questions on the employee's behalf. You cannot refuse a reasonable companion choice.

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Step 3: Conduct the Hearing

The purpose of the hearing is to hear from the employee, not to rubber-stamp a decision already made. Approach it as a genuine enquiry.

Structure of the hearing:

1. Introduce everyone present and note who is taking notes
2. Explain the purpose of the meeting
3. Set out the allegation(s) and present the evidence
4. Allow the employee (and their companion) to respond to each allegation
5. Ask any clarifying questions
6. Allow the employee to present their own evidence or call witnesses
7. Ask if there is anything else they want to say
8. Adjourn to consider the outcome (do not make a decision in the meeting if possible)

Take thorough notes during the hearing. These notes may become evidence in a tribunal.

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Step 4: Decide the Outcome

After the hearing, consider the evidence and make a decision. The outcome options are:

No further action: The allegation is not upheld. Inform the employee in writing promptly.

Written warning (first written warning): For a first instance of misconduct that is not gross misconduct. Sets out what the employee must do to improve and the consequences if they do not.

Final written warning: For repeated misconduct, a more serious first offence, or where a written warning has not led to improvement. Makes clear that dismissal is the next step if there is no improvement.

Dismissal with notice: For serious or repeated misconduct, or where a final written warning has not led to improvement. The employee receives their contractual or statutory notice period.

Summary dismissal (dismissal without notice): Only for gross misconduct, where the evidence is clear and the process has been followed. Payment in lieu of notice is also an option for gross misconduct.

Demotion or transfer: In some cases (especially where dismissal seems disproportionate), moving the employee to a different role or location may be an appropriate alternative. Only possible where the contract allows it, or where the employee agrees.

Proportionality: The outcome must be proportionate to the misconduct. Dismissing someone for a first offence of minor lateness would be unfair. Dismissing someone for a first offence of punching a colleague would not.

Consistency: Consider how you have treated similar cases in the past. Inconsistency is a common ground for unfair dismissal claims.

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Step 5: Communicate the Outcome

Communicate the outcome to the employee as soon as reasonably possible after the hearing (usually within a few days).

The outcome letter should include:

• The decision and the reason for it
• If a warning: what improvement is required and by when, and what the consequence of further misconduct will be
• If dismissal: the reason for dismissal, the notice period, and final pay entitlements
• The right of appeal and how to exercise it
• The deadline for appealing (typically five working days)

Give the outcome letter at a follow-up meeting or send it promptly in writing. Do not delay.

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Step 6: Allow the Right of Appeal

Every employee who receives a disciplinary sanction must be offered the right to appeal. This is a key requirement of the ACAS Code.

The appeal process:

• The employee submits a written appeal within the deadline (typically five working days)
• The appeal is heard by a more senior manager or director, not the person who heard the original hearing
• The appeal is a review of the decision, not a complete rehearing (though it can include new evidence)
• The outcome is communicated to the employee in writing

At appeal, the outcome can be upheld, reduced (for example, a dismissal reduced to a final written warning), or overturned.

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Managing Warnings: How Long Do They Last?

Disciplinary warnings do not last forever. Your policy should state how long each level of warning remains "live":

• First written warning: typically 6 months (though some employers use 12 months)
• Final written warning: typically 12 months (some employers use 18-24 months for serious misconduct)

Once a warning expires, it cannot be used as the basis for the next level of sanction. You can take it into account as background, but you cannot treat an employee with an expired warning as being on a final warning.

Set calendar reminders for warning expiry dates. Keep a record of all warnings issued.

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Gross Misconduct: Key Points

If you are dealing with a gross misconduct allegation:

• Suspend the employee on full pay during the investigation (if their presence is a risk)
• Carry out a thorough investigation before the hearing
• Give them the full right to respond at the hearing
• Do not assume the outcome before the hearing
• If dismissing summarily: ensure the evidence of gross misconduct is clear and unambiguous

Even in gross misconduct cases, a fair process is required. A dismissal without any investigation or hearing is unfair, even if the employee did commit the act.

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Disciplinary Process Checklist

• [ ] Investigation completed before any formal hearing
• [ ] Invitation letter sent with specific allegations and evidence
• [ ] At least five working days' notice given of the hearing
• [ ] Employee informed of right to be accompanied
• [ ] Companion request accommodated (or reasonable alternative offered if companion unavailable)
• [ ] Hearing conducted genuinely, employee given full opportunity to respond
• [ ] Notes taken at hearing
• [ ] Decision adjourned (not made at the hearing)
• [ ] Outcome proportionate to the misconduct
• [ ] Outcome consistent with how similar cases have been handled
• [ ] Outcome communicated in writing promptly
• [ ] Right of appeal offered with clear deadline
• [ ] Appeal heard by different manager
• [ ] All records retained securely

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FAQ: Disciplinary Procedure UK

Can I dismiss someone informally if they are still in their probationary period?

Not safely, no. Even during probation, dismissing without any process is risky. From January 2027, an employee has unfair dismissal rights after six months. A short probationary process (meeting, chance to respond, written outcome, right of appeal) is appropriate even for probationary dismissals.

What if the employee refuses to attend the hearing?

If the employee fails to attend a hearing without good reason, you can proceed in their absence after rescheduling once. Give them reasonable opportunity to attend or be represented. Document your attempts to accommodate them.

Do I need a witness to attend the hearing?

Having a notetaker at the hearing is strongly recommended. Notes taken at the time are contemporaneous evidence. A hearing conducted without a notetaker is harder to defend if challenged.

What is the difference between a verbal warning and a written warning?

In most disciplinary procedures, the stages are: verbal warning (informal), first written warning, final written warning, dismissal. A verbal warning is typically used for a first minor issue and may not be part of your formal procedure. A written warning starts the formal disciplinary record. Make sure your policy clearly states the stages and what each one means.

Can I dismiss someone without any prior warnings?

Yes, if the misconduct is gross misconduct. One act of gross misconduct can justify summary dismissal with no prior warning history, provided you have followed a fair investigation and hearing process. For ordinary misconduct (as opposed to gross misconduct), dismissal without prior warnings is likely to be found unfair.

What should I do if an employee raises a grievance during disciplinary proceedings?

A grievance raised during disciplinary proceedings does not automatically pause the proceedings. Consider whether the grievance is related to the disciplinary matter. If it is unconnected, you can deal with both in parallel. If it is related (for example, the employee claims they were treated unfairly in the investigation), you may need to consider whether to pause the disciplinary process while the grievance is investigated.

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Get Your Disciplinary Procedure Checked

An outdated or incomplete disciplinary procedure is one of the most common reasons employers lose unfair dismissal claims at tribunal.

EmployerKit Audit from £49. We check your disciplinary procedure against the ACAS Code and ERA 2025 requirements and tell you exactly what needs updating.

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Last updated: April 2026