Employee Grievances Against a Manager: What UK Employers Should Do

When an employee raises a grievance against manager conduct, many UK employers make the same mistakes. They treat it as a personality clash, let the manager handle it informally, delay the process until the problem grows, or focus only on whether the complaint is "serious enough" instead of whether their process is fair. Those missteps can turn a manageable workplace issue into a resignation, a discrimination claim, or a wider team problem.

A grievance against manager behaviour needs a careful, even-handed response. The right approach protects your business, supports the employee, and gives the manager a fair opportunity to respond. It also helps you spot whether the complaint points to bullying, harassment, poor management practice, a whistleblowing issue, or a contractual breach.

This guide explains what a grievance against manager means for UK businesses, what legal issues to check before you act, the common mistakes employers make, and how to handle the process in a way that is practical and legally safer.

Overview

A grievance against manager conduct is a formal workplace complaint made by an employee about the actions, decisions, behaviour, or treatment they have received from their manager. UK employers should deal with it promptly, fairly, confidentially, and in line with their grievance procedure and the Acas Code of Practice on disciplinary and grievance procedures.

The main legal risk is usually not the fact that a complaint was raised. The bigger risk is mishandling it through delay, bias, poor record-keeping, retaliation, or an inadequate investigation.

• Check whether your grievance policy clearly covers complaints about line managers and senior staff.
• Confirm who should handle the grievance if the usual manager is the subject of the complaint.
• Decide whether the issue may also involve bullying, discrimination, harassment, whistleblowing, health and safety, or breach of contract.
• Investigate the facts before reaching a view, including documents, messages, witnesses, and prior complaints.
• Keep written records of the complaint, meetings, evidence reviewed, findings, and any outcome.
• Protect the employee from victimisation for raising concerns.
• Consider interim steps if the working relationship has broken down, such as changed reporting lines or temporary separation.
• Offer an appeal handled by someone impartial and more senior where possible.

What Grievance Against Manager Means For UK Businesses

A grievance against a manager is not just an HR issue, it is a legal and operational issue that can affect staff retention, culture, and risk exposure across the business.

In practice, these complaints often arise in founder-led businesses and SMEs where reporting lines are close, policies are basic, and managers wear several hats. An employee may say their manager has bullied them, undermined them in meetings, denied leave unfairly, changed duties without discussion, excluded them, shouted at them, or treated them differently because of a protected characteristic.

Some complaints are about management style rather than unlawful conduct. Others point to something much more serious. Your job as an employer is not to assume either way at the outset. Your job is to run a fair process and reach a reasoned conclusion.

What counts as a grievance?

A grievance is any concern, problem or complaint an employee raises about their work, workplace, or working relationships. It can be raised informally at first, but once the issue is put forward as a formal complaint, especially in writing, you should treat it under your grievance procedure.

A grievance against a manager might involve:

• alleged bullying or intimidation
• harassment, including sexual harassment
• discrimination linked to age, disability, race, sex, religion or belief, sexual orientation, pregnancy, gender reassignment, marriage or civil partnership
• unfair allocation of shifts, pay, commission or opportunities
• unreasonable performance management
• breaches of flexible working arrangements or agreed hours
• victimisation after a previous complaint
• health and safety concerns
• retaliation connected to whistleblowing
• breach of contract or inconsistent treatment compared with others

Why the complaint needs independent handling

If the manager complained about is also the person who normally receives grievances, you need a different decision-maker. This is where smaller businesses often get caught. A process will not look fair if the accused manager controls the evidence, attends every meeting, or influences the outcome.

Where possible, appoint someone impartial. That may be another senior manager, a founder who is not directly involved, or an external HR or legal adviser supporting the process. The key point is that the person hearing the grievance and the person deciding any appeal should be as independent as your business structure allows.

Why process matters even if the complaint seems weak

A weak complaint can still create legal risk if you mishandle it. An employee may later claim constructive dismissal, discrimination, harassment, or victimisation, arguing that the business ignored concerns or punished them for speaking up.

Tribunals often look closely at process. They may consider whether the employer followed its own policy, whether the employee was heard, whether evidence was properly reviewed, and whether the business acted consistently with the Acas Code. Failing to follow a fair process can increase exposure even where the underlying facts are disputed.

How this interacts with contracts and policies

Your employment contracts and workplace policies shape how these complaints should be handled. Before you rely on a verbal promise or an informal approach, check the documents your staff already have.

You should review:

• employment contracts
• staff handbook provisions on grievance, bullying, harassment and equality
• disciplinary procedures if misconduct may also be involved
• whistleblowing policies
• absence, stress and wellbeing policies
• data protection and monitoring policies where messages, CCTV or IT records may be reviewed

If your documents are outdated, vague or inconsistent, that can make the process harder. It can also create confusion about timeframes, rights to be accompanied, appeal rights, and who has authority to make decisions.

Legal Issues To Check Before You Sign

Before you sign off on any grievance outcome, resignation response, settlement discussion, warning, or management action, check the legal character of the complaint and whether your process would stand up to scrutiny.

1. Follow the Acas Code and your own grievance procedure

The Acas Code is not legislation, but it matters. Employment tribunals take it seriously, and compensation can be adjusted in some cases if an employer unreasonably fails to follow it.

At a practical level, this usually means you should:

• invite the employee to explain the grievance
• investigate the complaint without unreasonable delay
• hold a meeting to discuss it
• allow the employee to be accompanied where the legal right applies
• give a written decision
• offer an appeal

If your internal policy gives more detail, you should usually follow that too unless there is a clear reason not to.

2. Check for discrimination, harassment and victimisation risk

If the grievance mentions unfair treatment linked to a protected characteristic, treat that as a discrimination risk issue from the start. Do not reduce it to a simple interpersonal dispute.

Harassment can include unwanted conduct related to a protected characteristic that violates someone's dignity or creates an intimidating, hostile, degrading, humiliating or offensive environment. Sexual harassment has its own legal framework and should be handled with particular care.

Victimisation risk often arises after the grievance is raised. If the employee is sidelined, denied work, marked down, or treated coldly because they complained, that can become a separate legal problem even if the original grievance is not upheld.

3. Consider whether whistleblowing is involved

Some grievances are really whistleblowing disclosures in disguise. If the employee says the manager pressured staff to break the law, ignore safety rules, falsify records, misuse personal data, or mislead clients, you may be dealing with protected disclosure issues as well as a grievance.

This matters because workers have protection against detriment and dismissal for whistleblowing. Before you classify the complaint as a routine management dispute, check what exactly the employee is alleging.

4. Watch for constructive dismissal triggers

If the employee says trust and confidence have broken down, or threatens to resign unless action is taken, the complaint may be heading toward a constructive dismissal argument. The law in this area is fact-sensitive, but a poor response can make the position worse.

That does not mean you must accept every allegation. It means you should avoid knee-jerk reactions, casual dismissals of the complaint, or forcing the employee back into an unsafe reporting line before you have investigated.

5. Handle evidence lawfully and proportionately

You may need to review emails, instant messages, meeting notes, CCTV, diary entries, performance records, and witness statements. You should do this in a way that is relevant, proportionate and consistent with your data protection obligations and privacy notice.

Think carefully before you:

• circulate the grievance more widely than necessary
• disclose witness identities without considering fairness and confidentiality
• search personal devices without a lawful basis
• rely on covert recordings without taking advice
• retain investigation records indefinitely

Confidentiality matters, but it is not absolute. You usually cannot promise that nobody will know about the complaint if you need to investigate it properly.

6. Decide whether interim measures are needed

If the complaint involves serious bullying, harassment, or a breakdown in working relations, temporary steps may be sensible before the investigation ends. These are not a finding of guilt. They are risk-management measures.

Depending on the situation, that could include:

• temporary changes to reporting lines
• adjusted shifts or duties
• limited contact between the employee and manager
• a different manager conducting performance reviews
• paid suspension of the manager in serious misconduct cases, where justified and carefully handled

Choose the least disruptive option that still protects staff and the integrity of the process.

7. Separate grievance issues from disciplinary findings

A grievance process is about investigating the complaint and deciding whether it is upheld. If your findings point to misconduct by the manager, you may then need a separate disciplinary process.

Founders often blur the two. They tell the employee the complaint is "dealt with" because the manager had a quiet word, or they jump straight to disciplining the manager without a proper grievance outcome. Both approaches can create fairness problems.

8. Keep appeal rights real, not cosmetic

An appeal should be a genuine review, not a rubber stamp. If possible, it should be heard by someone not previously involved and more senior than the original decision-maker.

Where your business is too small for perfect separation, document the limitation and make sure the appeal still addresses the employee's concerns carefully and independently.

Common Mistakes With Grievance Against Manager

The most common mistake is treating a grievance against a manager as an inconvenience instead of a formal risk issue that needs a fair process.

Letting the accused manager control the process

This happens often in small businesses. The manager drafts the response, chooses the witnesses, or sits in on the grievance meeting. That undermines trust in the process and can taint the outcome.

Move control of the complaint to someone else as early as possible.

Trying to keep it "informal" for too long

Informal resolution can work for minor misunderstandings, but not where there are allegations of bullying, discrimination, retaliation, or repeated poor treatment. If the employee has clearly raised a formal complaint, do not keep pushing mediation or off-the-record chats as a substitute for the process.

Before you rely on a verbal promise that "we'll sort it out", ask whether the facts actually require an investigation.

Focusing only on intent, not impact

Employers often defend a manager by saying they did not mean to upset anyone. Intent can be relevant, but it is not the only question. The effect of the conduct matters, especially in harassment cases.

Look at what was said or done, the context, any pattern of behaviour, and how a reasonable person would view it.

Poor note-taking and weak evidence handling

If there is no clear paper trail, it becomes much harder to defend your decision later. Basic process gaps include missing meeting notes, no witness records, unclear findings, and vague outcome letters.

Your records should show:

• what the employee alleged
• what evidence was reviewed
• who was interviewed
• what findings were made on each issue
• what action was taken and why
• what right of appeal was offered

Retaliation after the grievance

This is a major risk area. A manager who feels accused may reduce the employee's hours, exclude them, scrutinise them more heavily, or create pressure for them to leave. Even subtle retaliation can become the real legal issue.

Monitor what happens after the complaint, not just during the investigation.

Ignoring the wider team issue

Sometimes one grievance reveals a pattern. If several people have left the same team, or there have been previous informal complaints, your business may have a management or culture problem rather than a one-off disagreement.

That may justify wider action, such as management training, policy updates, an external review, or changes to reporting structures.

Using settlement conversations too early

Some employers try to resolve things quickly by discussing an exit package before they have investigated the complaint. That can be risky. It may look like you are trying to remove the complainant rather than address the issue.

Settlement discussions can be appropriate in some situations, but they should be carefully timed and documented. They are not a shortcut around a fair internal process.

Forgetting the manager is also entitled to fairness

You can take the complaint seriously without assuming guilt. The manager should know the substance of the allegations, have a chance to respond, and be treated consistently with your procedures.

A one-sided process can create problems on both sides, especially if disciplinary action later follows.

What a sensible process looks like in practice

For most SMEs, a workable grievance process against a manager will usually include:

1. acknowledging the complaint promptly and confirming who will handle it
2. deciding whether any immediate temporary measures are needed
3. gathering the key evidence and identifying witnesses
4. meeting with the employee to understand the allegations fully
5. giving the manager a fair chance to respond
6. making findings on each main allegation
7. sending a written outcome with reasons
8. offering an appeal and managing post-outcome working arrangements

The detail depends on the seriousness of the allegations, the size of your business, and whether other legal issues are engaged. The core principles are fairness, neutrality, evidence, and proper documentation.

FAQs

Does every grievance against a manager need a formal investigation?

No, not every complaint needs a long or complex investigation. But if the grievance alleges bullying, discrimination, harassment, retaliation, serious unfairness, or repeated conduct, a formal process is usually the safer approach.

Can the employee refuse to work with the manager during the grievance?

Not automatically, but you should consider whether temporary changes are reasonable while the complaint is investigated. If there is a genuine wellbeing, safety, or victimisation concern, interim measures may be appropriate.

Can we reject the grievance if there is no hard proof?

You can reach findings based on the evidence available, including witness accounts and surrounding documents. The question is not whether there is criminal-level proof, but whether you carried out a fair investigation and reached a reasonable conclusion.

Should the accused manager be suspended?

Only sometimes. Suspension should not be automatic. It may be justified in serious cases, especially where there is a risk to staff, evidence, or the integrity of the process, but less restrictive options should be considered first.

What if the employee resigns before the grievance is finished?

You should still consider whether to complete the process, especially if the allegations raise legal, cultural, or safeguarding concerns. A resignation does not erase the underlying risk to the business.

Key Takeaways

• A grievance against manager conduct should be handled as a formal business risk, not dismissed as a personality issue.
• Use a fair and impartial process, especially where the usual manager is the subject of the complaint.
• Check whether the complaint also raises discrimination, harassment, whistleblowing, victimisation, health and safety, or contractual issues.
• Follow your grievance policy and the Acas Code, keep clear records, and offer a genuine appeal.
• Consider interim measures where needed, but avoid assuming guilt before the facts are investigated.
• Watch what happens after the grievance, because retaliation and poor handling often create bigger legal exposure than the original complaint.

If you want help with grievance procedures, workplace policies, employment contracts, and bullying or discrimination policies, you can reach us on 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.

Official Sources to Check

Rules and regulator guidance can change. Check the current official material most relevant to this issue before relying on the article:

• Acas: employment law and workplace guidance