If the employer has decided to investigate a disciplinary or grievance issue, they should start as soon as possible.
This is to make sure they're treating the employee fairly. For example, people might remember a situation more clearly the sooner they're asked about it.
Who can carry out the investigation
The employer should get somebody who's not involved in the case to carry out the investigation, for example another manager or someone from HR. This is to make sure there is no conflict of interest.
If this is not possible, they should try and make the procedure as impartial as they can.
Where possible, the person investigating should also have had training. They should also have a good knowledge of their organisation's policy on investigations. Acas offers training courses in handling disciplinary and grievance procedures, including courses on conducting investigations.
When choosing an investigator, the best choice will often depend on how serious and complex the case is – for example, if it involves potential gross misconduct, discrimination or bullying. For investigations like this, it might be best to appoint someone more senior or experienced.
External consultants
In exceptional circumstances, it might be appropriate to appoint an external consultant. They can be more detached from the matter and bring an independent view. However, this can cost more and take longer. It should also be in line with company policy.
In a disciplinary case
In a disciplinary case, the employer should think about who will handle matters if further action is needed.
Where possible, a different person should handle each of the following steps of the disciplinary procedure:
- the investigation
- the disciplinary hearing and outcome
- the appeal hearing (if an appeal is raised)
The person handling the disciplinary hearing should have the authority to make a decision on the outcome.
In a grievance case
For a grievance investigation, it is usually best for the person hearing the grievance to investigate the issue.
Role of the investigator
The role and responsibilities of the investigator should be clearly explained in their 'terms of reference'. These should include:
- what needs to be investigated
- whether they are expected to give recommendations at the end of the investigation
- how their findings should be set out
- who their findings should be reported to
Clear terms of reference can help to:
- complete the investigation quickly
- clarify the investigator's remit
- ensure all key facts are investigated
Making an investigation plan
The employer and the person investigating, if there is one, should start by making an investigation plan.
This can include:
- what needs to be investigated
- who is carrying out the investigation
- 'witnesses' – anyone who needs to be spoken with to find out about the issue
- any sources of evidence – for example work records, emails or CCTV recordings
- any time limits – for example CCTV footage being deleted or staff going on leave
- timeframes
- policies or organisation guidelines to follow
- setting out the importance of confidentiality
- any other relevant points or information
A clear plan can help to:
- make the investigation as quick and easy as possible
- make clear exactly what needs to be done
- make sure the process is full and fair
- maintain good working relationships
Employers and investigators can download and use the Acas template for an investigation plan.
Telling the employee
The employer or person investigating should tell the employee with the disciplinary or grievance issue as soon as they decide to start an investigation.
This is unless the employer thinks there is a risk that the employee might tamper with evidence or influence witnesses. In this case, the employer should wait until there is less risk of this.
When the employer tells the employee they are starting an investigation, it's a good idea for them to explain:
- why they're carrying out an investigation
- that the meeting is only to establish the facts and is not a disciplinary meeting
- who will be carrying it out
- what they're going to do
- that they'll need to talk to any witnesses
- how long it could take
- what will happen next, for example a meeting
- who they can contact if they have any questions or concerns during the investigation – usually the investigator, their manager or HR
Employers can use the Acas letter templates for:
- disciplinary cases – informing an employee they are the subject of an investigation
- grievance or disciplinary cases – inviting an employee to an investigation meeting
Keeping it confidential
An investigation should usually be kept confidential. This can help to:
- reduce any negative impacts to all involved
- maintain good working relationships
- reduce the risk of witnesses discussing or agreeing what their evidence should be
- follow data protection law
It's important to explain the need for confidentiality. However, an employee should be allowed to discuss the investigation with a trade union or workplace representative, where they have one.
It should be made clear that if an employee breaches confidentiality, it could lead to disciplinary action.
Find out more about data protection from the Information Commissioner's Office (ICO).
Deciding whether to suspend an employee
If there's a serious issue or situation, an employer might consider suspending someone while they investigate.
An employer should consider each situation carefully. Suspension will only be needed in some situations.
If an employer feels they need to suspend someone, it's important to consider:
- alternative options to suspension
- the wellbeing of the person they're thinking of suspending – being suspended can be stressful and affect someone's mental health
Find out more about suspension during an investigation
Looking after employees' wellbeing and mental health
Being under investigation can be very stressful, so it's important that employers consider the wellbeing and mental health of their employees.
Looking out for employees' wellbeing and offering support can help prevent:
- absence
- mental health problems arising
- existing mental health conditions getting worse
For example, the employer should keep in regular contact with the employee. They could also arrange any meetings in a more private and comfortable location if this would help an employee.