How to conduct a disciplinary investigation

Not every allegation requires a formal investigation — minor issues can be dealt with informally. An investigation is required when you are considering formal disciplinary action. The more serious the potential outcome (e.g. dismissal), the more thorough the investigation must be.

Appoint someone to lead the investigation who has not been involved in the incident and who will not chair the disciplinary hearing. In small businesses where this is not possible, document why the same person is carrying out both roles. The investigating officer should be trained or briefed on their role before starting.

Suspension should only be used where there is a genuine risk to the business, other employees, or the investigation itself — for example, where there is a risk of evidence being tampered with or where relationships have broken down. Suspension is not a disciplinary sanction and should be on full pay. It should be reviewed regularly and kept as short as possible.

Collect all relevant evidence before interviewing the employee. This may include: CCTV footage, emails, messages, timesheets, attendance records, witness statements, company policy documents, and any relevant correspondence. Preserve evidence in its original form where possible. Note the date and time you gathered each piece of evidence.

Interview any witnesses to the alleged conduct. Witnesses should be interviewed separately and privately. Explain that the conversation is confidential and that they should not discuss the investigation with colleagues. Take a written note of each interview and ask the witness to read and sign it as an accurate record. Do not put words in witnesses' mouths — use open questions.

Invite the employee to an investigatory meeting in writing. Explain that the meeting is investigatory — it is not a disciplinary hearing and no disciplinary action will be taken at this stage. The employee does not have a statutory right to be accompanied at an investigatory meeting, though you may choose to allow it. Ask open questions and give the employee a full opportunity to respond to the allegations. Take a written note.

Produce a written investigation report summarising: the allegations, the evidence gathered, what each witness said, what the employee said, and your findings on the facts. The report should conclude whether there is a case to answer — i.e. whether, on the balance of probabilities, the alleged conduct occurred. The report does not decide on sanction — that is for the disciplinary hearing.

Based on the investigation report, decide whether there is sufficient evidence to proceed to a formal disciplinary hearing. If not, close the matter and inform the employee in writing. If yes, write to the employee inviting them to a disciplinary hearing, enclosing copies of all the evidence that will be relied upon.