D-BRIEF – Employment & Pensions Blog: A guide to grievance investigations

There are many reasons why an employee may decide to raise a grievance. Whilst in some cases grievances can be resolved informally, where this is not possible employers will generally be required to carry out an investigation. Conducting a thorough investigation is important, not just to the employee who raised the grievance but also to the employer, as it will reduce the risk of successful tribunal claims and help avoid any negative impact on staff morale. Below we consider steps an employer should take when carrying out a grievance investigation.

ACAS Code of Practice

When investigating a grievance, a good starting point is the ACAS Code of Practice. The Code encourages employers to act promptly and consistently and to investigate thoroughly to establish the facts. The Code also sets out a number of principles of good practice, including allowing the employee to be accompanied at meetings and providing the employee with a right of appeal. An Employment Tribunal has the power to increase a compensation award by up to 25% where an employer unreasonably fails to follow the Code of Practice, so employers are encouraged to ensure their policies reflect the Code to ensure compliance.


Appointing the investigator

Consideration should be given to who within the organisation is best placed to investigate the grievance. This is often the line manager but the key principles are that an investigator should be independent and should have no involvement with the allegations.

Where the employer is unable to appoint an independent investigator from within the organisation, an external investigator may be appointed. An external investigator can also be considered where particular specialist knowledge is required or where allegations are made against senior employees. Whilst there will be costs associated with the appointment of an external investigator, it should ensure that the investigation is fair and impartial and will minimise the risk of a successful challenge on the process followed.

Gathering and analysing evidence

The investigator should not only consider evidence in support of the allegations, but also evidence that undermines the allegations. The investigator should aim to gather enough evidence to enable understanding and a reasoned decision to be made and should be mindful that further evidence may come to light during the course of the investigation. Possible sources of evidence include witness accounts, CCTV, emails, phone logs, social media, training records, appraisal notes, sickness absence records and medical records.

Generally, an investigation report should be prepared setting out the evidence and the findings. The report should also set out how the investigation process was conducted, what evidence was considered and the details of any witnesses interviewed.  The strengths and weaknesses of the evidence must be assessed and the findings of the investigator outlined, including what facts have been established and a consideration of any mitigating factors.

Notes and audit trail

Detailed notes should be kept throughout each stage of the investigation to assist with any future tribunal claims which may be brought against the employer. Insofar as possible, the employer should be able to explain the rationale for any decisions taken.

Concurrent processes

A grievance is often raised as a reaction to other internal processes such as disciplinary or performance management.  Whether or not it is reasonable to run the grievance and the other process concurrently, or pause the other internal process to investigate and deal with the grievance, will depend on the detail of the grievance and whether the processes are linked.

Our team are experienced in carrying out grievance investigations on behalf of clients where an independent investigator is needed. For further information on this or grievance investigations more generally, please contact a member of our Employment Team.

Share this publication

Related categories

Employment Blog


The latest news from Devonshires, sent to you direct.

Join our mailing list and find out what we’re up to and what we think about recent events and future possibilities.

Join our Mailing List