A disciplinary procedure exists to address concerns about an employee's conduct or performance in a fair, consistent, and legally defensible way. In the UK, the ACAS Code of Practice on Disciplinary and Grievance Procedures sets the minimum standard that employment tribunals expect employers to follow.
Failing to follow the ACAS Code doesn't automatically make a dismissal unfair, but an employment tribunal can increase any compensation award by up to 25% if an employer unreasonably fails to comply.
The Legal Framework
Disciplinary procedures in the UK are governed by:
- ACAS Code of Practice 1 — the primary standard for disciplinary and grievance procedures
- Employment Rights Act 1996 — unfair dismissal provisions
- Equality Act 2010 — prohibition on discriminatory disciplinary action
- Human Rights Act 1998 — right to a fair hearing
Every employer with more than one employee should have a written disciplinary procedure. This should be included in the employee handbook or employment contract, and shared with employees on day one.
Before You Start: Is It Conduct or Capability?
The first question to ask is whether the issue is one of:
- Conduct — the employee is choosing to behave in an unacceptable way (e.g. persistent lateness, insubordination, dishonesty)
- Capability/Performance — the employee lacks the skills, knowledge, or health to do their job
Conduct issues follow the disciplinary procedure. Capability issues often call for a separate performance improvement process, though the procedural steps are similar. Mixing the two can cause problems — be clear from the outset which process you are running.
Step 1: Initial Investigation
Before taking any formal action, carry out an investigation to establish the facts.
What investigation involves:
- Gathering documents (timesheets, CCTV footage, emails, complaint records)
- Speaking to witnesses informally
- Reviewing the employee's previous record
Key rules:
- The investigator should ideally be different from the person who will chair the disciplinary hearing
- Keep investigation notes — these may be needed as evidence at a tribunal
- Do not pre-judge the outcome
Should you suspend the employee?
Suspension should only be used when there is a genuine need — for example, where the employee's presence could hinder the investigation or pose a risk. It should never be used as a punishment.
If you do suspend, do so on full pay (unless the contract expressly allows unpaid suspension) and tell the employee:
- They are suspended pending investigation
- Suspension is not an assumption of guilt
- When you expect to be back in touch
Step 2: Invite to a Disciplinary Hearing
If the investigation reveals there is a case to answer, invite the employee to a formal disciplinary hearing.
The invitation letter must include:
- The nature of the alleged misconduct or performance issue
- The date, time, and location of the hearing
- The employee's right to be accompanied
- Copies of any evidence you intend to rely on
- Confirmation that a possible outcome could be a formal sanction (including dismissal if relevant)
Give the employee enough time to prepare — ACAS recommends at least 5 working days' notice where possible, though urgency can sometimes shorten this.
The Right to Be Accompanied
Under the Employment Relations Act 1999, employees have a statutory right to be accompanied at a disciplinary hearing by:
- A trade union representative (even if you don't recognise a union)
- A colleague (a fellow worker employed by you)
The companion can address the hearing and confer with the employee, but cannot answer questions on the employee's behalf.
Note: employees do not have a statutory right to bring a friend, family member, or solicitor — though you may allow this at your discretion.
Step 3: Conduct the Disciplinary Hearing
The hearing is the employee's opportunity to respond to the allegations. Approach it with an open mind — the outcome should not be decided before the hearing takes place.
Hearing structure:
- Introductions — explain who is present and their role
- Confirm the right to be accompanied (and whether companion is present)
- State the allegations clearly
- Present your evidence
- Give the employee the opportunity to respond — this is critical
- Allow the employee to ask questions, call witnesses, or present their own evidence
- Adjourn before reaching any decision
During the hearing:
- Take detailed notes (or have a separate note-taker present)
- Stay calm and professional — do not let the hearing become adversarial
- If new information emerges, consider adjourning to investigate further
Adjourning to decide:
Never announce the outcome at the end of the hearing. Always adjourn, consider the evidence, consult HR or a solicitor if needed, then communicate the outcome separately.
Step 4: Deciding the Outcome
After the hearing, review the evidence and decide on an appropriate sanction (or no sanction if the allegation is not upheld).
The Disciplinary Sanctions
Verbal warning (first warning)
- Used for minor first-time misconduct
- Usually live on the employee's file for 6 months
- Should still be confirmed in writing
First written warning
- Used for more serious misconduct, or repeat minor misconduct after a verbal warning
- Usually live for 12 months
Final written warning
- Used when previous warnings have not led to improvement, or for serious misconduct falling short of gross misconduct
- Usually live for 12 months (sometimes 24 for very serious matters)
Dismissal with notice
- Used when previous warnings have not been effective, or for serious (but not gross) misconduct
- Employee is entitled to their contractual or statutory notice
Summary dismissal (dismissal without notice)
- Reserved for gross misconduct only
- Gross misconduct is conduct so serious that it fundamentally destroys the employment relationship
Examples of Gross Misconduct
Common examples include:
- Theft, fraud, or dishonesty
- Physical violence or threats of violence
- Serious harassment, bullying, or discrimination
- Gross insubordination
- Serious breach of health and safety rules
- Unauthorised disclosure of confidential information
Your contract or handbook should define gross misconduct for your business — don't rely on implied examples alone.
Consistency
Before deciding on a sanction, check how similar cases have been handled before. Inconsistency in applying discipline is a common reason for successful unfair dismissal claims.
Step 5: Communicate the Outcome
Write to the employee within a reasonable time after the hearing (usually within 5 working days).
The outcome letter should include:
- The decision and the reasons for it
- The nature of any sanction imposed
- How long the warning will remain live
- What improvement or change is expected (for warnings)
- The right to appeal and how to do so
- (If dismissal) the effective date and notice entitlement
Step 6: The Right of Appeal
Every employee must be given the right to appeal against any formal disciplinary sanction, including dismissal.
Appeal procedure:
- The employee should submit their appeal in writing, stating the grounds
- The appeal should ideally be heard by a different, more senior person than the original decision-maker
- The appeal hearing follows the same format as the original hearing
- The outcome can uphold, overturn, or vary the original decision
Appeals are not a formality — treat them seriously. An appeal is often the last chance to correct a procedural error before a tribunal claim.
Special Situations
Absence during disciplinary proceedings
If an employee is absent (e.g. on sick leave) during a disciplinary process, you cannot simply abandon the procedure. Take advice from an occupational health professional if needed. If an employee repeatedly fails to attend hearings without good reason, you may be able to proceed in their absence — but document everything carefully.
Long-standing employees
Length of service does not exempt an employee from discipline, but a clean long record is a mitigating factor when deciding the appropriate sanction.
Protected characteristics
Be especially careful where the conduct being disciplined may be linked to a protected characteristic (disability, religion, pregnancy, etc.). Taking disciplinary action that disproportionately affects employees with a particular characteristic could constitute indirect discrimination.
Reasonable adjustments for disabled employees
Under the Equality Act 2010, employers must make reasonable adjustments for disabled employees throughout the disciplinary process. Examples include:
- Allowing a support worker or advocate in addition to the statutory companion
- Providing documents in accessible formats
- Holding meetings in an accessible location
- Allowing additional breaks during hearings
- Considering whether the disability may have contributed to the conduct in question
- Giving extra time to prepare or respond to allegations
Failure to make reasonable adjustments can result in a separate discrimination claim on top of any unfair dismissal claim.
Probationary employees
Employees in their probationary period have fewer legal rights, but best practice is still to follow a fair process. Note that employees need 2 years' continuous service to bring an unfair dismissal claim (with some exceptions).
Writing Your Disciplinary Policy
Every employer should have a written disciplinary procedure in place. Your procedure should cover:
1. Scope and purpose
- Confirm who the procedure applies to
- State that the procedure is non-contractual (recommended)
2. Informal stage
- Minor issues should be dealt with informally first
- A quiet word or management instruction is often enough
3. Investigation
- Who will investigate and how
- Whether suspension may be necessary and on what basis
4. Notification
- How the employee will be informed of allegations
- Minimum notice period for hearings
5. The hearing
- Right to be accompanied
- How evidence will be presented
- Who will chair the hearing
6. Outcomes and warnings
- Types of warnings available
- How long warnings remain active (typically 6 or 12 months)
- What constitutes gross misconduct in your organisation
7. Appeals
- How to submit an appeal
- Timescale for appeal hearings
- Who will hear the appeal
HR Systems and Disciplinary Records
A good HR system keeps a complete audit trail of:
- Investigation notes and evidence
- Invite letters and hearing notes
- Outcome letters
- Appeal correspondence
- Warning expiry dates
Grove HR automatically tracks warning statuses and expiry dates, ensuring you're always working with up-to-date disciplinary records rather than relying on spreadsheets.
Common Mistakes to Avoid
| Mistake | Risk |
|---|---|
| Skipping investigation | Unfair dismissal finding |
| Pre-judging outcome | Fair hearing challenge |
| Not giving enough notice of hearing | Procedural unfairness |
| Forgetting right to be accompanied | Statutory breach |
| Announcing decision at the hearing | No time to consider evidence |
| Not offering appeal | ACAS Code breach (up to 25% uplift) |
| Applying sanctions inconsistently | Discrimination or unfairness claim |
| Poorly kept records | Unable to defend at tribunal |
Key Takeaways
Following a fair disciplinary procedure protects both the employee and the employer. The ACAS Code is your minimum baseline — document everything, give the employee a genuine opportunity to respond, and always offer an appeal.
When in doubt, take advice before acting. Employment tribunal claims are expensive, time-consuming, and reputationally damaging even when the employer wins.
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Rachel Richardson
Head of Growth & Marketing, Grove HR
Rachel leads growth and marketing at Grove HR, with over a decade of experience in UK HR technology. She writes practical guides to help small businesses navigate employment law and build better workplaces.
Frequently Asked Questions
Do I have to follow the ACAS Code of Practice?
The ACAS Code of Practice is not legally binding, but employment tribunals take it into account when deciding unfair dismissal claims. If you unreasonably fail to follow the Code, a tribunal can increase any compensation award by up to 25%. In practice, following the Code is essential for any employer.
Can I dismiss someone without a disciplinary hearing?
You should not dismiss an employee without giving them the opportunity to respond at a disciplinary hearing, except in the most exceptional circumstances. Even in gross misconduct cases, the employee must be given a fair hearing before dismissal. Dismissing without a hearing is a common cause of unfair dismissal findings.
How long do written warnings stay on file?
There is no fixed legal requirement, but ACAS guidance suggests first written warnings should typically remain live for 12 months and final written warnings for 12-24 months. After this period, the warning should be disregarded for disciplinary purposes (though it remains on the file as a record). Your disciplinary policy should set out your specific timescales.
What counts as gross misconduct?
Gross misconduct is conduct so serious that it fundamentally destroys the employment relationship, justifying immediate dismissal without notice. Common examples include theft, fraud, violence, serious harassment, and gross insubordination. Your employee handbook should list examples relevant to your business — but this list is illustrative, not exhaustive.
Can I discipline someone who is on sick leave?
Yes, but you must proceed carefully. You cannot simply wait indefinitely for someone to return. Seek an occupational health assessment if needed to understand the employee's fitness to participate in hearings. If the employee repeatedly fails to engage without good reason, you may be able to proceed in their absence — but document every step and take legal advice first.


