ACAS Grievance Procedure: A Guide for UK Employers on Handling Employee Complaints

If you run a business with employees in the UK, there’s a good chance you’ll face a workplace grievance at some point-whether it’s a complaint about management, bullying, discrimination, or terms of employment. Knowing how to handle these situations fairly and professionally is crucial. That’s where the ACAS grievance procedure comes in.

Getting your grievance process right isn’t just about ticking a box. It’s about building a positive workplace culture, managing legal risks, and keeping problems from getting bigger (and more costly) down the line. In this article, we’ll break down the ACAS grievance procedure, why it matters for employers, and how to put it into practice. We’ll also guide you through best practices, required policies, and key legal compliance steps-so you’re protected from day one.

Let’s take a closer look at what you need to know about ACAS grievance procedure and why following it is an essential part of running your business.

What Is the ACAS Grievance Procedure?

The ACAS grievance procedure is the step-by-step best practice guide published by the Advisory, Conciliation and Arbitration Service (ACAS) to help UK employers resolve workplace complaints fairly and legally. It sets out a recommended process for handling employee grievances-meaning any formal concerns, issues, or complaints raised relating to their work, their manager, or the working environment.

While you’re not legally required to follow the exact ACAS Code of Practice, employment tribunals will look closely at whether you did during a dispute. Not following the ACAS guidelines without good reason could mean any tribunal award against your business is increased by up to 25%. So, even though the procedure itself isn’t law, it’s risky to ignore it.

Why Should Employers Follow the ACAS Grievance Procedure?

Handling grievances in line with the ACAS procedure is more than a formality. Here’s why it matters:

• It helps avoid legal disputes and tribunals. A clear, fair process makes it less likely that employee complaints will escalate to a lawsuit or tribunal-saving you stress, time, and money.
• It demonstrates compliance with the Employment Rights Act 1996 and Equality Act 2010. Proper grievance handling is part of your duty to provide a safe, fair workplace and avoid discrimination, harassment, or victimisation claims.
• It builds workplace trust and morale. Staff will feel more secure and valued if they know complaints are taken seriously and handled consistently.
• It gives your business protection and clarity. You’ll have a solid paper trail and evidence that you followed best practice, which is useful if a dispute does arise.

Put simply: following the ACAS grievance procedure is a proven way to manage risks and set your business up for long-term success.

What Counts as a Grievance Under the ACAS Procedure?

“Grievance” is quite a broad term-so what does it actually cover?

An employee might raise a grievance about issues including:

• Bullying, harassment, or discrimination (on grounds like race, sex, disability, religion, age, etc.)
• Pay, hours, or changes to working conditions
• Management style or treatment by colleagues or supervisors
• Health and safety concerns
• Flexible working requests (and perceived unfair refusals)
• Unfair application of polices or procedures
• Opportunities for progression or training

Grievances can be raised informally at first, but the process we’re talking about here focuses on formal written grievances that require structured employer action.

What Are the Stages of the ACAS Grievance Procedure?

The ACAS Code of Practice outlines four key steps employers should take when dealing with grievances:

1. Let the Employer Know: The employee raises their grievance, preferably in writing, and explains their concerns clearly and in detail.
2. Hold a Meeting: You investigate and hold a meeting with the employee. The employee has the right to be accompanied by a colleague or trade union representative.
3. Take Action: After considering any evidence and discussion at the meeting, you provide a written decision outlining your findings and any actions you propose to take.
4. Offer an Appeal: If the employee isn’t happy with the outcome, they have the right to appeal. A different manager (where possible) should handle the appeal stage impartially.

This step-by-step approach demonstrates transparency and good faith. Let’s look at each stage in more detail-and what it means for your responsibilities as an employer.

Step 1: Receiving the Grievance

Grievances should ideally be raised in writing, so there’s a clear record of what the concerns are. Your own employee policies or staff handbook should outline how to submit a grievance, who to contact, and what information should be included.

If an employee raises a concern verbally, best practice is to ask them to confirm their complaint in writing (email is fine). This ensures everyone is on the same page from the start.

Step 2: Investigation and Meeting

Once you receive a grievance, act promptly to carry out any necessary investigation. Gather relevant facts, speak to witnesses if needed, review documents or records, and keep the process confidential wherever possible.

You’ll then invite the employee to a formal grievance meeting. The invitation should:

• Explain the purpose of the meeting
• Let the employee know they can bring a companion
• Provide enough time to prepare

During the meeting, allow the employee to fully explain their concern, ask questions, and present evidence. If you need more time to investigate further, arrange to reconvene.

Remember, handling meetings and investigations poorly-or appearing not to take them seriously-can open you up to employment claims. It’s wise to keep thorough written notes at each stage.

Step 3: Written Decision and Action

Once you’ve heard the grievance and gathered all necessary facts, it’s time to decide what to do about it. You must notify the employee in writing of:

• The outcome of the grievance (including full reasons)
• Any actions you plan to take, such as adjustments at work, further training, or changes to procedures
• The employee’s right of appeal if they are unhappy with the decision

This written response forms a crucial part of your records, especially if there’s a challenge to your decision later on.

Step 4: Handling Appeals

If the employee appeals, arrange another meeting with a different (usually more senior) manager wherever possible. Listen to why the employee feels the original decision was wrong or incomplete, review any new evidence, and consider the case afresh.

After the appeal meeting, provide a written outcome. The result is usually final, though sometimes a grievance might trigger a more extensive policy or compliance review in your business.

What Written Grievance Policies Do Employers Need?

Under UK law, all employers must provide workers with a written statement of employment particulars, including how to raise a grievance. In practice, this means you’ll need a clear grievance policy-usually as a standalone document and as part of your staff handbook or workplace policies.

A good grievance policy will:

• Explain what counts as a grievance
• Set out who to contact and how to submit a complaint
• Describe the steps you’ll follow in line with the ACAS Code
• Outline the right to be accompanied at meetings
• Clarify the process for appeals
• Emphasise confidentiality and the prohibition of victimisation

It’s essential your policies are tailored to your unique business-not copied from a generic template-so they actually protect you when a real issue arises. If you need to create or review your grievance policy, our team can help you put together one that’s both compliant and practical.

What Are the Legal Risks of Not Following the ACAS Grievance Procedure?

Failing to follow the ACAS grievance procedure or your own written policies can lead to significant problems:

• Tribunal penalties: Employment tribunals can increase any award by up to 25% if you did not follow the ACAS Code without good reason.
• Unfair dismissal claims: Mishandling a grievance (especially if it relates to harassment, discrimination, or whistleblowing) can mean dismissals are ruled unfair, leaving your business exposed to hefty compensation orders. See our guide on lawful employee dismissal.
• Discrimination and victimisation claims: Ignoring or mishandling grievances related to protected characteristics can trigger claims under the Equality Act 2010. For guidance, see our article on workplace harassment and discrimination.
• Damage to reputation and workplace culture: If grievances are handled badly, you risk increased resignations, poor morale, or even whistleblowing to regulators.

The bottom line: Having clear, compliant grievance procedures-and using them every time-protects you from avoidable legal headaches.

What Else Should Employers Know About Handling Grievances?

Keep Records and Ensure Confidentiality

Maintain detailed records at every stage of the process (including notes of meetings, evidence considered, outcomes, and letters sent). This protects your business and ensures you can show compliance if ever challenged.

Keep everything confidential throughout, only involving those who genuinely need to know. Breaching confidentiality could undermine trust or even form the basis of a legal claim.

Treat Everyone Consistently and Fairly

A cornerstone of the ACAS procedure is consistency-apply your grievance process to all staff, regardless of position or length of service. Inconsistent handling can lead to allegations of bias or discrimination.

Look for Root Causes and Learn

If the same types of grievance crop up regularly, that’s a sign your working environment or policies might need reviewing. Effective grievance handling isn’t just about resolving individual issues-it’s a chance to learn, improve, and build a happier team.

Can Employers Offer Informal Resolution?

Absolutely! ACAS itself encourages informal resolution wherever appropriate, especially for less serious problems between colleagues. An informal chat might fix minor concerns before they become formal grievances. However, don’t discourage staff from using your full grievance process if needed.

If the grievance is serious (e.g. involves bullying, discrimination, or a legal risk), stick to the formal ACAS procedure from the start. If in doubt, always err on the side of transparency and compliance.

Do Employers Need Legal Support for Grievance Procedures?

Employers aren’t legally required to use a lawyer for handling grievances, but smart business owners nearly always get tailored legal support-especially if:

• You need help drafting or reviewing your grievance policies
• A complaint involves discrimination, whistleblowing, or protected characteristics
• The case is complex (e.g. involves multiple allegations or cross-claims)
• There could be a risk of an employment tribunal claim

Professional guidance ensures your process is watertight and helps avoid common pitfalls that can arise from trying to ‘do it yourself’. Having a robust company policy in place from the beginning can make all the difference. And if you do face a claim, having followed the ACAS procedure (with legal oversight) will always put you in a stronger position.

Frequently Asked Questions on the ACAS Grievance Procedure

Do I have to follow the ACAS Code of Practice?
You’re not legally obliged, but failing to do so can result in higher penalties at tribunal. Sticking to the ACAS Code is considered best practice and will protect you if things escalate.

Can employees bring companions to grievance meetings?
Yes, employees have a legal right to be accompanied by a colleague or union rep at any formal grievance or appeal meeting.

Do I need to let employees appeal grievance outcomes?
Yes, a right of appeal is an ACAS requirement-and it must usually be handled by someone not previously involved.

What if the grievance is against a manager or director?
Follow your policy-usually another manager or a director at the next level up hears the case. If your business is small, consider independent HR or legal support for extra impartiality.

Are oral grievances covered?
You should encourage complaints to be made in writing, but if an employee raises an oral grievance, treat it just as seriously.

Key Takeaways: ACAS Grievance Procedure for Employers

• The ACAS grievance procedure sets a standard for fair, legal handling of workplace complaints-and tribunals expect you to follow it.
• Grievances must be handled promptly, consistently, and confidentially. Your grievance policy should outline every step.
• Failing to follow best practice risks tribunal penalties, unfair dismissal claims, and reputational damage.
• Always give employees the right to appeal, keep written records, and take every grievance seriously.
• Invest in tailored policies and legal advice-avoiding templates and DIY approaches-to keep your business protected from day one.

If you need help drafting or reviewing your grievance procedures, employee policies, or handling complex complaints, don’t go it alone. Our friendly team at Sprintlaw can guide you through every step of the ACAS grievance procedure-ensuring legal compliance without the stress.

For a free, no-obligation chat, contact us at 08081347754 or team@sprintlaw.co.uk. We’re here to help you build strong, legally protected workplaces across the UK.