ACAS Disciplinary Procedures: 5-Step Process [2026 Guide]

What is the ACAS Code of Practice?

The Advisory, Conciliation and Arbitration Service (ACAS) publishes a statutory Code of Practice on Disciplinary and Grievance Procedures. While not legally binding in itself, employment tribunals are required to take the Code into account when considering relevant cases. If an employer unreasonably fails to follow the Code, a tribunal can increase any compensation award by up to 25%.

The Code sets the minimum standard. Employers should have their own, more detailed disciplinary procedure that meets or exceeds the Code's requirements.

What is the ACAS disciplinary process?

Step 1: Establish the Facts

• Conduct a thorough investigation before any disciplinary action
• Gather evidence (statements, documents, CCTV if relevant)
• The investigation should be conducted by someone who will not chair the disciplinary hearing
• Do not pre-judge the outcome

Step 2: Inform the Employee

• Write to the employee setting out the allegations against them
• Include enough detail for them to understand the case and prepare a response
• Provide copies of evidence that will be relied upon
• Give reasonable notice of the disciplinary hearing
• Inform them of their right to be accompanied

Step 3: Hold a Meeting

• The meeting should be held without unreasonable delay
• Give the employee a full opportunity to state their case
• Allow them to respond to each allegation
• Consider any mitigating circumstances
• Adjourn if further investigation is needed

Step 4: Decide and Communicate the Outcome

• After the meeting, decide the appropriate action
• Inform the employee in writing of the decision and the reasons
• Where a warning is given, specify the improvement required and the timeframe
• State the consequences of further misconduct

Step 5: Provide a Right of Appeal

• The employee must be offered the right to appeal
• The appeal should be heard by someone more senior who was not involved in the original decision
• The appeal hearing should review the original decision and consider any new evidence
• Communicate the appeal outcome in writing

What are the disciplinary sanctions?

The Code does not prescribe specific sanctions, but common practice in UK workplaces follows this progression:

1. Informal action: Verbal discussion for minor first-time issues
2. First written warning: For misconduct or continued poor performance after informal action
3. Final written warning: For serious misconduct or failure to improve after a first warning
4. Dismissal: For gross misconduct (summary dismissal without notice) or failure to improve after a final warning

Gross Misconduct

Some offences may justify dismissal without prior warnings. Examples typically include:

• Theft or fraud
• Physical violence
• Serious health and safety breaches
• Serious insubordination
• Bringing the organisation into serious disrepute

Even for gross misconduct, a fair investigation and hearing must still take place.

What is the right to be accompanied?

Under the Employment Relations Act 1999, employees have the statutory right to be accompanied at formal disciplinary and grievance hearings by:

• A work colleague, or
• A trade union representative

The companion can address the hearing, confer with the employee, and sum up the case, but cannot answer questions on the employee's behalf.

What are the common mistakes in disciplinary procedures?

• Skipping the investigation: Proceeding straight to a hearing without gathering facts
• Predetermining the outcome: Deciding the sanction before the hearing takes place
• Not allowing the right to be accompanied: This is a statutory right, not optional
• No right of appeal: The Code explicitly requires this
• Inconsistency: Treating similar cases differently can amount to unfair treatment
• Acting too hastily or too slowly: Both carry risks

How Grove HR Helps

Grove HR provides disciplinary process templates aligned with the ACAS Code, letter generators for each stage (invitation to investigation meeting, disciplinary hearing invite, outcome letter, appeal invitation), document storage for case files, and an audit trail that demonstrates a fair and consistent process.