HR Consultancy Services
Workplace investigation services
When a serious complaint lands, how you respond matters as much as what you decide. A fair, thorough and impartial investigation protects your people and your organisation. A flawed one is one of the most common reasons employers lose at tribunal.
At Cornerstone Resources, we provide independent workplace investigations and fact finding for employers across the UK. Whether you need an external investigator to take the whole process off your hands, or HR support for your own managers, we’re here to help.
Independent & impartial · UK-wide · In person or remote
When a grievance is raised or a disciplinary issue surfaces, someone has to establish the facts. That’s harder than it sounds. The investigator needs to be impartial, available, trained in interviewing, and senior enough to be credible. Though for most organisations, anyone who fits that description is likely to be too close with the people involved.
That’s where an independent workplace investigation helps. We act as the external investigator: gathering evidence, interviewing witnesses and producing a clear, balanced report of findings that you can rely on when deciding what happens next. The decision always stays with you; it’s our job to make sure it rests on facts that have been established fairly, in line with the ACAS Code of Practice.
You can learn more about the investigation process by reading our practical guide for employers.
When an independent workplace investigation is the right approach
An HR investigation needs to be (and seen to be) fair. Independence matters most when the allegations are serious, when the people involved are senior, or when there’s simply no one internally who can investigate without a conflict of interest.
Not sure whether to investigate formally? If you’re uncertain whether a situation calls for a formal investigation at work, a facilitated conversation, a workplace mediation, or an informal resolution, we’ll give you an honest view before anything is commissioned.
- Grievance investigations, where an employee has raised a formal complaint that needs to be examined impartially
- Disciplinary investigations and fact finding into allegations of misconduct, before any disciplinary hearing takes place
- Bullying, harassment and discrimination investigations, including dignity-at-work complaints, where sensitivity and a fair workplace harassment investigation process are essential
- Whistleblowing and safeguarding investigations, including protected disclosures and concerns raised in churches and charities
- Cases involving senior leaders, trustees or HR itself, where no internal investigator could credibly be seen as neutral
Our Approach
How our workplace investigation process works
Our investigation process follows the ACAS Code of Practice and is built around the TCM FRESH approach — Fair, Rigorous, Equitable, Sensitive and Honest — to ensure every investigation is thorough, proportionate and fair to everyone involved.
Scoping and terms of reference
Every investigation starts with clear terms of reference. We agree the allegations to be investigated, the evidence likely to be needed, who will be interviewed, and realistic timescales. Defining the scope up front keeps the workplace investigation process proportionate and prevents it drifting into areas it was never meant to cover.
Evidence gathering and interviews
We review the relevant documents, policies and records, then interview the complainant, the person under investigation and any witnesses. Interviews are structured, even-handed and properly documented, so that every party has a fair opportunity to give their account.
Findings report
You receive a clear written report setting out the evidence, the facts we've been able to establish on the balance of probabilities, and where instructed, findings on whether there is a case to answer. The report gives the decision-maker a sound, defensible basis for the next steps.
We establish facts. You make decisions. An investigator’s role is to find out what happened, not to decide the outcome. Keeping those roles separate is a core part of a fair process — and it’s what makes the findings stand up to scrutiny.
Honest Assessment
When you may not need an external investigator
Not every issue needs an independent investigation and it’s important to us that we’re straightforward about this. Many day-to-day matters can and should be handled internally by a trained manager.
An external workplace investigation is usually unnecessary where:
- The matter is minor and a quick, informal fact-finding conversation would resolve it
- A capable, impartial manager is available internally and the allegations aren’t against anyone senior
- The real issue is a relationship breakdown rather than misconduct; in which case a workplace mediation is likely the better route
- The facts aren’t actually in dispute, and what’s needed is a decision, not an investigation
- The matter is being dealt with by the police or another statutory body, and an internal process needs to wait
If you’d rather keep the investigation in-house, we can support your managers with guidance, interview frameworks and documentation.
Learning and Development
Managing investigations & disciplinaries: practical training for managers
A two-hour live online session that builds the confidence and practical skills your managers need to handle investigations and disciplinary processes fairly — reducing legal risk and getting the procedure right first time.
- When to intervene early versus pursue formal action
- How to conduct a fair, proportionate workplace investigation
- Disciplinary hearing fundamentals aligned to the ACAS Code
- Managing difficult conversations with greater confidence
Next session
Thursday 9 July 2026
10:00–12:00 UK time
Price
£595 + VAT
Unlimited attendees per organisation
Why Cornerstone
Why choose Cornerstone as your workplace investigation consultant?
Genuinely independent
We have no history with the people involved and no stake in the outcome. That independence protects the integrity of the process and protects you if the outcome is ever challenged at tribunal.
Straightforward findings, not what you want to hear
Our reports say what the evidence supports, even when that's uncomfortable. If the complaint is upheld, you'll know why. If it isn't, you'll have a documented, defensible basis for saying so.
The broader HR picture, built in
As an HR consultancy, we understand the employment law context, the ACAS Code and the business risk sitting behind every employee investigation. Our investigators know how findings will be used, so reports are written to be genuinely useful to decision-makers.
Available across the UK
We deliver workplace investigations across the UK, in person or remotely, and can move quickly. We understand that in a live grievance or suspension situation, delay is itself a risk.
Meet your investigators
Experienced, impartial professionals
Investigations are led by senior members of our consultancy team, each with hands-on experience of grievance, disciplinary and harassment casework across SMEs, charities and churches.
Rob Birley
Rob is a co-founder of Cornerstone Resources and a Senior HR Consultant specialising in Employee Relations. Since establishing Cornerstone in 2018, he has led casework across commercial and faith-sector organisations, bringing a thorough, evidence-focused approach to grievance, disciplinary and misconduct investigations.
Nicci Birley
Nicci is a co-founder and Senior HR Consultant with more than 20 years of experience across national and global organisations. She brings a structured, people-centred approach to sensitive casework including investigations in churches, charities and the voluntary sector.
Andrea Ferguson
Andrea is a TCM-accredited workplace mediator and investigator with over 30 years of experience in HR, both in-house and as a consultant. She brings a calm, structured approach to sensitive casework and is available for in-person and remote work across the UK.
Julie Welling
Julie has over 30 years of HR experience across hospitality, retail, FMCG, SMEs and charities. She brings deep operational expertise to her investigation work, with a particular focus on supporting smaller organisations where an independent, professionally run process makes the greatest difference.
What Clients Say
Trusted with the sensitive cases
“I've worked with Rob on an employment issue and found him to be extremely professional, both in his understanding of the case and also the manner in which it was handled. As a small business with no HR department, in the future it'll be beneficial to be able to call on his expertise and navigate through various issues as they arise, knowing there will be a cost effective solution available.”
Martin Taylor
Director, Peloton Events
Google review
“As a small business owner, it is invaluable to have someone like Cornerstone Resources on hand to help with the tricky employment issues. Highly recommend.”
Stephen W.
Director, Swift Tree Services
Google review
Ready When You Are
Need something investigating?
If a grievance, complaint or allegation has landed on your desk, the worst thing you can do is let it sit. Timescales contribute towards fairness, your people and the way the process looks if it’s ever examined.
Talk to us. We’ll listen, give you a clear view of the options and, if an investigation is the right route, we can get started quickly.
FAQ
Frequently asked questions
An HR investigation (or workplace investigation) is a formal fact-finding process used to establish what happened when a grievance, disciplinary allegation or complaint is raised at work. The investigator gathers documents, interviews the people involved and produces a report of findings, which the employer then uses to decide on next steps. It is a fact-finding exercise, not a hearing. The investigator establishes facts rather than deciding outcomes.
As long as necessary and no longer. ACAS guidance is that investigations should be completed without unreasonable delay. A straightforward grievance investigation may take one to two weeks; complex cases involving multiple witnesses can take longer. We agree timescales in the terms of reference at the outset and keep all parties informed if anything changes.
The report goes to the commissioning manager or decision-maker. The person under investigation will normally be entitled to see the report (or relevant findings) if the matter proceeds to a disciplinary hearing, and parts may be disclosable in response to a subject access request or in tribunal proceedings. We write every report on the assumption that it may one day be read by a tribunal.
Yes. This is one of the most common reasons employers commission independent workplace investigations. Where the person complained about is senior, or where HR itself is conflicted, an external investigator is often the only way to run a process that is demonstrably impartial.
Costs depend on the scope: the number of allegations, witnesses to be interviewed and the volume of documentation. We agree the scope and give you a clear indication of expected costs before any work begins. Contact us for a quote based on your situation.