Back to Impact Hub

guide

Workplace Investigations: A Guide for UK Employers

SECTION GUIDE

How to conduct fair and compliant workplace investigations: A guide for UK employers

When something goes wrong at work, whether it’s a misconduct allegation, grievance or whistleblowing complaint, your response matters.

Workplace investigations aren’t just a formality. Handled well, they show your business takes employee concerns seriously, protects your culture, and avoids unnecessary legal risk. But if the process is mishandled, even with good intentions, the consequences can be costly: reputational damage, tribunal claims, lost productivity, or even losing valued staff.

So how can employers ensure that their employment investigations are fair, thorough, and legally compliant?

In this article, we’ll break down the steps involved, common mistakes to avoid, and how to approach investigations with confidence and clarity.

Workplace Investigationsimpact hr ident

  • What is a workplace investigation?

    An employment investigation is a structured process used by employers to gather and review evidence when a serious concern is raised in the workplace.

    Common reasons for investigations include:

    • Allegations of employee misconduct (e.g. bullying, harassment, dishonesty)
    • Formal grievances or complaints from team members
    • Discrimination or victimisation claims
    • Concerns raised via whistleblowing procedures

    • Breaches of company policies or procedures

    It’s vital that all investigations are approached impartially, with proper planning and thorough documentation. Employers must also follow the Acas Code of Practice on Disciplinary and Grievance Procedures—failure to do so could increase a tribunal award by up to 25%.

  • Why workplace investigations matter

    Failing to carry out a fair investigation can lead to:

    • Unfair dismissal claims
    • Breaches of employment law
    • Breakdown of trust among staff
    • Damage to your employer brand

    In contrast, a well-run investigation can:

    • Protect your business from legal and financial risk
    • Build employee confidence and transparency
    • Resolve issues faster and more professionally
    • Improve your HR policies and future processes

Step-by-Step: How to conduct a fair employment investigation

Here’s a practical, best-practice approach employers should follow when dealing with any workplace complaint or allegation:

  • 1. Act promptly

    As soon as a concern is raised, take initial steps to assess the issue. Delays can undermine the credibility of your response, increase risk, and damage morale.

  • 2. Check your policies

    Refer to your grievance, disciplinary or whistleblowing policies. If you don’t have these documented, seek external HR support to apply a fair process.

  • 3. Appoint a trained, neutral investigator

    The person conducting the investigation should not be personally involved in the matter. They must be impartial, have appropriate training, and the time to conduct the process thoroughly.

  • Workplace Investigations

  • 4. Define the cope of the investigation

    What are you investigating? What’s the allegation? What evidence or individuals will be involved? Set clear parameters and stick to them.

  • 5. Gather evidence carefully

    This may include:

    • Interviewing relevant employees
    • Reviewing documentation (emails, policies, logs)
    • Taking signed statements
    • Recording notes during every meeting

  • 6. Give all parties the right to respond

    An employee accused of misconduct must have the chance to respond to the concerns raised. This is a fundamental part of a fair process.

  • 7. Document everything

    From interview notes to decisions taken, ensure you maintain a clear audit trail. This can form the basis of any further disciplinary or grievance steps.

  • 8. Make a decision and take action

    Once the investigation is complete, decide whether further formal action is needed. If yes, the next step might be a disciplinary hearing. If no action is needed, close the investigation and record the outcome.

  • Common investigation mistakes to avoid

    Even well-meaning businesses can fall foul of process if they’re not careful. Common pitfalls include:

    • Not starting the investigation quickly enough

    • Investigators showing bias or pre-judging the outcome

    • Lack of clear documentation

    • Failure to communicate properly with employees

    • Skipping the investigation entirely and going straight to dismissal

    Mistakes like these don’t just risk legal claims—they damage your culture and erode employee trust.

  • Legal requirements for employers

    Under UK employment law, employers must ensure that all disciplinary and grievance processes follow a fair and consistent procedure.

    The Acas Code of Practice is not legally binding but is used by employment tribunals when assessing whether an investigation or dismissal was fair. Non-compliance can result in increased compensation being awarded to employees.

    Additionally, employers must uphold their obligations under the Equality Act 2010, Data Protection Act, and any relevant case law.

When to bring in external HR support

Many businesses don’t have internal HR expertise or feel too close to the issue. That’s when outsourcing the investigation makes sense.

At impact HR we regularly support SMEs and larger employers across Essex and the UK with:

  • Independent investigations
  • Grievance and disciplinary advice
  • HR policy reviews
  • Manager training on fair process

  • Support for complex employee relations cases

We provide impartial, compliant advice and conduct investigations on your behalf where needed.

Where to find out more A collection of hand-picked useful resources from impact HR and beyond

Make an enquiry

Let’s talk

Start making your impact.

Whether you need day-to-day HR support, ad-hoc support or a long-term partner, we’re here to help.

Get in touch for a free initial chat — no pressure, just practical advice from people who get it.

0330 2369866
hello@impacthr.co.uk

Leicester: 6 St. Georges Way, 3rd Floor, St. George’s House, Leicester LE1 1QZ
London: 167 City Road, London EC1V 1AW
Leeds: Building 3, City West Business Park, Gelderd Rd, Holbeck, Leeds LS12 6LN
Essex: Halford House, 2 Coval Lane, Chelmsford, England, CM1 1TD