One of the most common questions employers ask when a workplace issue arises is, “How long will the investigation take?”
The answer depends on the complexity of the matter, the availability of evidence and witnesses, and the seriousness of the allegations being investigated. However, regardless of the circumstances, workplace investigations should always be conducted without undue delay.
Acting promptly helps preserve evidence, supports employee wellbeing, and demonstrates that the organisation is taking concerns seriously. Delays can make investigations more difficult, increase organisational risk, and undermine confidence in the process.
An investigation should begin as soon as reasonably possible after a concern, complaint, allegation or issue has been raised. Early action is important because valuable evidence can quickly become unavailable.
For example:
Starting promptly allows investigators to secure evidence while events are still fresh in people’s minds.
There is no fixed timescale that applies to every workplace investigation. Some investigations can be completed within a few hours or days, particularly where the issues are straightforward and the evidence is readily available.
More complex investigations may take several weeks, particularly where multiple witnesses need to be interviewed or large amounts of documentation require review. Employees may also be absent or unavailable for some time, or additional lines of enquiry may emerge during the investigation.
The key principle is that investigations should be completed within a reasonable timeframe based on the circumstances of the case. For example, if you find out about a potential misconduct six months after it happened – the clock starts now, not 6 months ago.
Conversely, if you conducted an investigation, found evidence of serious misconduct and did not take action, it is unlikely to be reasonable to take action months after finding the evidence if there is not a good reason for the delay, such as the incapacity of the subject of the investigation.
One of the most effective ways to manage timescales is through careful planning. Before beginning the investigation, consider:
A clear investigation plan helps ensure enquiries remain focused and that resources are available when needed. It also provides evidence that the organisation acted reasonably if decisions are challenged later.
Acting promptly is particularly important where evidence may be time-sensitive.
Examples include:
CCTV footage: Many CCTV systems automatically delete recordings after a set period. If footage may be relevant, it should be identified and secured as soon as possible.
Electronic records: Emails, messaging systems and other digital records can be altered or deleted if action is delayed.
Witness accounts: Memories naturally fade over time. Interviewing witnesses promptly often results in more accurate and reliable evidence.
Employees who have raised concerns, those who are the subject of allegations, and witnesses may all feel anxious while waiting for an outcome. Good communication helps manage expectations throughout the process. Where appropriate, employees should be informed about the investigation process with an anticipated timescale, then updated if there are any significant delays, and informed of next steps.
Regular updates can help maintain confidence in the investigation and reduce unnecessary frustration.
Where an employee has been suspended, timescales become particularly important. Suspension should not continue longer than necessary. Employers should ensure investigations progress without undue delay and regularly review whether suspension remains appropriate.
Unnecessarily prolonged investigations can increase stress, damage working relationships and create additional employee relations issues.
Investigators should keep a record of key dates and actions throughout the process. This may include:
A clear timeline helps demonstrate that the investigation was managed reasonably and professionally. If the matter progresses to an appeal or Employment Tribunal, these records may become important evidence.
Some of the most common causes of unnecessary delays include:
Avoiding these issues helps ensure investigations remain fair, efficient and proportionate.
What is a workplace investigation?
How to conduct a workplace investigation
Who should investigate?
Suspensions during investigations
Interviewing witnesses
Confidentiality
Gathering evidence
Writing reports
Timescales
