2025 UK Employment Law Changes

Dismissal & Disciplinary 2 min read

How should employers conduct a disciplinary investigation?

Reviewed by Rebecca Hughes, Senior HR Consultant, CIPD Level 7 Last updated: 20 January 2026
Expert Answer

The investigation stage is arguably the most important part of the disciplinary process. A thorough, fair investigation protects the employer if the matter reaches a tribunal — while a rushed or biased investigation is one of the most common reasons employers lose unfair dismissal claims.

Appointing an Investigator

The person conducting the investigation should be separate from the person who will make the disciplinary decision. This separation of roles demonstrates impartiality. The investigator should:

  • Have no personal involvement in the matter
  • Be sufficiently senior to access relevant information
  • Understand the basics of employment law and fair process

Steps in the Investigation

1. Define the Scope

Clearly identify what is being investigated. What are the specific allegations? What evidence is needed? This prevents the investigation from becoming unfocused or expanding beyond its original purpose.

2. Gather Evidence

  • Documents: emails, messages, timesheets, CCTV footage, records, reports
  • Witness statements: interview relevant witnesses and record their accounts in writing. Witnesses should sign their statements.
  • Physical evidence: damaged property, stolen items, system logs

3. Interview the Employee

The investigation meeting is not a disciplinary hearing — it is an information-gathering exercise. The employee should be told:

  • What is being investigated
  • That this is an investigation, not a disciplinary hearing
  • That they may be accompanied (while there is no statutory right to be accompanied at investigation meetings, allowing it is best practice)

4. Consider Suspension

If the allegation is serious (e.g., gross misconduct) and the employee's continued presence could compromise the investigation or pose a risk, consider suspension on full pay. Suspension must be:

  • Kept as brief as possible
  • Reviewed regularly
  • Not used as a punishment
  • Communicated in writing with reasons

5. Compile the Investigation Report

The investigator should produce a written report covering:

  • The allegations investigated
  • Evidence gathered (with appendices)
  • Findings of fact
  • Recommendation on whether there is a case to answer at a disciplinary hearing

Common Investigation Mistakes

  • Deciding the outcome before investigating
  • Only gathering evidence that supports the allegation
  • Not interviewing all relevant witnesses
  • Taking too long — unreasonable delay undermines fairness
  • Not keeping written records

Need support running a fair investigation? Our disciplinary support team can guide or conduct investigations on your behalf. Get in touch.

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