Investigations for discipline and grievance: step by step

Step 2: Preparing for an investigation

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

Where possible the employer should get somebody who is not involved in the case to carry out the investigation, for example another manager or someone from HR.

This is to keep things as fair as possible. In smaller businesses, the employer might have to do it themself.

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 step of the disciplinary procedure that’s needed:

Where possible, the employer should assign a more senior person to handle the disciplinary hearing and outcome than the person assigned to the investigation.

In a grievance case

For a grievance investigation, it is usually best for the person hearing the grievance to investigate the issue.

You can find more details on choosing who to carry out the investigation in the Acas guide to conducting workplace investigations.

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
  • anyone who needs to be spoken with (‘witnesses’)
  • 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 workplace guidelines to follow
  • whether the person investigating is expected to give recommendations at the end of the investigation
  • 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
  • avoid negative effects on staff or the business

Employers and investigators can:

Telling the employee

The employer or person investigating should tell the employee with the disciplinary or grievance issue as soon as they decide to open 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 opening an investigation, it’s a good idea for them to explain:

  • why they’re carrying out an investigation
  • 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
  • that everything will be kept confidential

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

An investigation can be stressful for the employee in either disciplinary or grievance cases. It’s important for employers to consider the wellbeing and mental health of their employees and offer support where needed.

Deciding whether to suspend an employee in a disciplinary case

It’s normally best for an employer to avoid suspending an employee under a disciplinary investigation.

If necessary, the employer should make any other arrangements rather than suspension. For example, the employee could work somewhere else in the organisation temporarily.

The employer should only consider suspension during an investigation if they believe it’s needed to protect any of the following:

  • the investigation
  • the business
  • other employees
  • the employee under investigation

If suspension is necessary, the employer should:

  • explain to the employee the reason for their suspension
  • make clear it does not mean they believe the employee is guilty
  • still pay the employee in full throughout their suspension
  • keep the suspension confidential wherever possible
  • keep the suspension under close review
  • make sure it only lasts for as long as necessary
  • explain the employee’s responsibilities during their suspension, for example to not contact colleagues
  • name a person, such as their manager, the employee can contact if they have any concerns
  • keep regular contact with the employee throughout

Looking after employees’ wellbeing and mental health

Being suspended can be very stressful, so it’s important that employers consider the wellbeing and mental health of their employee.

Looking out for the employee's wellbeing and offering support can help prevent:

  • mental health issues arising
  • existing mental health issues getting worse

See more advice on supporting an employee with a mental health condition.