Responding to a Formal Grievance: What UK Employers Need to Get Right in the First Ten Days
The grievance letter usually arrives at an awkward moment. A Friday afternoon, the week of a pitch, or the day before someone goes on leave. And the first instinct is often to read it quickly, decide whether it seems fair, and then get back to it properly next week.
That gap between receiving a formal grievance and responding to it is where a surprising amount of commercial risk sits. Acas is clear that an employer should respond without unreasonable delay, and the way those first few days go tends to shape everything that follows: whether the employee stays, whether the issue widens to include the manager who took too long to reply, and whether the business ends up defending its process rather than the substance of the complaint.
Something we keep noticing is that grievances rarely escalate because the employer reached the wrong outcome. They escalate because the process felt improvised. Step 3 of the Acas grievance procedure is the point where a business either establishes that it takes concerns seriously or gives the employee a second complaint to make. The legal references in this article use the Acas framework for England, Wales and Scotland; Northern Ireland has a separate Labour Relations Agency Code.
What does responding to a formal grievance actually involve?
Responding to a formal grievance means acknowledging it promptly in writing, checking your own grievance procedure, choosing someone who can handle it fairly and is not personally implicated, deciding what investigation is needed, and arranging a grievance meeting. Acas Step 3 covers the response, records, confidentiality and investigation; Step 4 covers the formal meeting and the right to be accompanied where it applies.
The steps themselves are straightforward. The challenge for a growing business is making these decisions quickly, particularly when the person who would usually take the lead is named in the complaint or works closely with someone who is.
Who should handle it, and who should not
The person handling the grievance should not have been personally involved in the concerns raised, and their own decisions should not be under review. We know this can be genuinely difficult in a business of 40 people. If the grievance concerns the operations director, for example, the founder may feel like the natural person to step in, even where they appointed the director or previously supported the decision being questioned.
Where it is difficult to find someone genuinely impartial within the business, bringing in an independent investigator or chair can be a sensible and cost-effective option. It also gives everyone greater confidence in the process and helps address concerns about bias from the outset.
How quickly should you respond?
There is no statutory rule requiring a response within ten working days. Acas says grievance issues should be handled promptly and without unreasonable delay, and its step-by-step guidance says the grievance meeting should ideally be held within five working days, while allowing the employee enough time to prepare. A useful practical check is whether you could clearly explain the reasons for your timeline, in writing, if it were questioned later.
Delay is also legally live in its own right. In W A Goold (Pearmak) Ltd v McConnell [1995] IRLR 516, the Employment Appeal Tribunal confirmed an implied contractual term that employers will reasonably and promptly give employees an opportunity to obtain redress of a grievance. A serious failure to provide that opportunity can contribute to a constructive dismissal claim, separately from whatever the grievance was about.
Deciding how much investigation is needed
Not every grievance needs a full investigation. Treating a straightforward concern like a formal inquiry can make a small issue feel much bigger for everyone involved. The key is to take a proportionate approach: gather enough information to reach a fair, well-reasoned decision, without making the process more extensive than it needs to be.
Where the complaint involves bullying, discrimination or sexual harassment, a more thorough approach may be needed. Under the Worker Protection (Amendment of Equality Act 2010) Act 2023, in force from 26 October 2024, employers must take reasonable steps to prevent sexual harassment at work. A tribunal can increase compensation for sexual harassment by up to 25% where that preventative duty has been breached. The government’s July 2026 implementation timetable also schedules two further changes under the Employment Rights Act 2025 for 30 October 2026: employers will be required to take all reasonable steps to prevent sexual harassment of employees, and they will have a separate obligation not to permit harassment of employees by third parties such as clients and suppliers. This means the way a harassment grievance is handled may also show how seriously the business takes prevention more widely.
If a grievance is raised during a disciplinary process, Acas recommends considering whether the two matters should be handled separately or together, and whether it would be appropriate to pause the disciplinary. There is no single right answer, so it is helpful to record the reasons for the approach taken at the time.
Where grievance responses go wrong, and what that costs
The Acas Code of Practice on disciplinary and grievance procedures is not optional guidance in the ordinary sense. Under section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992, an employment tribunal can adjust an award in a relevant case by up to 25% where a party has unreasonably failed to follow the Code. That is a serious number attached to a process failure rather than to the underlying conduct.
Three employment cases illustrate the specific places where responses tend to come apart.
The right to be accompanied has a defined legal scope
Section 10 of the Employment Relations Act 1999 gives a worker the right to be accompanied at a grievance meeting where the complaint concerns a legal or contractual duty owed by the employer. The companion can be a fellow worker, a trade union representative, or an official employed by a trade union. In Toal and another v GB Oils Ltd [2013] UKEAT/0569/12, the EAT held that the requirement for the request to be reasonable does not give the employer a general right to veto an otherwise qualifying choice of companion. Acas says that if an employer is unsure whether the statutory right applies, allowing a companion is good practice.
Compensation in that case was low, but the practical point is not. Refusing a chosen companion in a rushed hearing invitation hands the employee a legitimate grievance about the grievance.
The appeal needs to be impartial
In Blackburn v Aldi Stores Ltd [2013] UKEAT/0185/12, the EAT held that an allegation that the employer had effectively denied a proper grievance appeal was relevant to the implied term of trust and confidence, and remitted the issue for reconsideration. The Acas Code says appeals should be handled impartially and, wherever possible, by a manager who has not previously been involved in the case.
Think it is worth considering who could hear any appeal before appointing the person who will decide the grievance. In a small leadership team, asking the most senior person to handle the grievance at the outset may mean there is no one sufficiently independent or senior to consider an appeal later.
A practical checklist for the first ten working days
The businesses that handle grievances well have usually put some of the groundwork in place before a concern is raised. This checklist covers the key actions to take during the first ten working days, but the order and timing may need to flex depending on the complexity and seriousness of the issues.
Acknowledge promptly in writing, confirm what you have received and what happens next. Aim to arrange the grievance meeting without unreasonable delay; Acas says ideally within five working days, while allowing reasonable time to prepare.
Check for any immediate risks, including conflicts of interest, safeguarding concerns, ongoing contact between those involved, potential retaliation and any support the employee may need. Consider whether temporary arrangements are necessary, taking care not to treat them as a disciplinary sanction or assume the outcome.
Re-read your own grievance procedure and follow it. Departing from your own written process is harder to defend than having a simple one.
Choose the people involved carefully. Decide who will investigate, who will chair the grievance meeting and who could hear any appeal. They do not always need to be different people, but each person should be able to act fairly, have no material conflict of interest and, wherever possible, not have been involved previously. Record the reasons for each appointment.
Decide and record the investigation scope, including the issues to be considered, the evidence and witnesses likely to be relevant, any matters that fall outside the scope and why, and how relevant records will be preserved. Keep the scope under review if new information emerges.
Invite the employee to the grievance meeting in writing, giving reasonable notice, explaining the purpose of the meeting and confirming who will attend. Include the right to be accompanied where it applies and ask whether any reasonable adjustments or other support are needed. Where the legal entitlement to a companion is uncertain, Acas says allowing one is good practice.
Consider any reasonable adjustments or practical support needed for the process. This may include adjustments relating to disability or neurodivergence, language or communication support, remote attendance, additional breaks, alternative formats or arrangements for an employee who is unwell or absent from work.
Handle personal data carefully and explain that information will be shared only where reasonably necessary to investigate and decide the grievance. Do not promise absolute confidentiality. Investigation notes and witness statements are likely to contain personal data, and an employee may later make a subject access request. Third-party information and other exemptions can affect what must be disclosed.
Keep a clear note of decisions, conversations, evidence gathered, agreed actions and the reasons for the approach taken. Records made at the time are usually more reliable and useful than an account reconstructed several months later. Keep notes factual, relevant and securely stored.
What this looks like in a real business
We were engaged by a business after an employee exit that had not gone as intended. It had escalated into both an appeal and a formal grievance, including concerns about process failings and claims of discrimination. The leadership team had acted with positive intent and were taken aback by the nature and extent of the claims raised, so they asked us to provide independent support to resolve the case fairly and identify any wider organisational learning (JourneyHR, Grievances, Investigations, Hearings + Appeals).
We ran an independent investigation covering the exit, the appeal and the grievance, evaluating decision-making, documentation and process adherence, and looking at how the agency actually operated day to day rather than how its policies said it should. What we found is the part worth sitting with: managers had consistently shown good intent and real commitment to their teams, but a lack of structure, clarity and confidence in applying best practice had allowed issues to drift.
The appeal and grievance were resolved with a clear, structured approach that gave closure to everyone involved. We then designed a management development programme built around the agency's own scenarios rather than generic training, focused on performance management, probation, recruitment decision-making and inclusive leadership.
That sequence is the useful bit for a founder. The grievance was the presenting issue. The actual commercial problem was that managers were not confident enough to act early, and no amount of careful grievance handling fixes that on its own.
How JourneyHR can help
We are a People and Culture consultancy, founded in 2010, and we are regularly brought in as external partners on grievances, investigations, hearings and appeals, particularly where impartiality inside the business is difficult or the complaint involves a senior leader.
We can work alongside your internal team or act as your independent investigator or hearing chair, across the whole grievance and disciplinary process: acknowledgement and policy review, investigation and evidence gathering, the written report, chairing the hearing, and a properly separate appeal. Where a formal process is not the right route, our workplace mediation support often resolves things faster and with less damage to the working relationship.
For businesses that want this capability standing by rather than sourced in a hurry, our retained HR support models combine HR Director thinking on the difficult judgement calls with experienced consultants handling the process itself. You can see how the models work on JourneyHR’s How We Work page.
If you have a grievance in front of you now, or you would rather sort out who handles these before one arrives, we are happy to talk it through and tell you honestly what we think the sensible route is.
Get in touch: https://www.journeyhr.com/contact
Final thought
Most employees who raise a formal grievance are not looking for a fight. They want to know that the business will listen, take their concerns seriously and handle the process fairly. Much of that confidence is built in the first week through the tone of the response, the speed of communication and the people chosen to manage the process. Get those foundations right and, even where the employee does not agree with the outcome, they are more likely to feel that the process was fair. It also gives the business the best chance of resolving the issue well and moving forward.
FAQs
How long does an employer have to respond to a formal grievance in UK?
There is no fixed statutory deadline. Acas says grievance issues should be dealt with promptly and without unreasonable delay, and its step-by-step guidance says the grievance meeting should ideally be held within five working days while allowing enough time to prepare. Your own written procedure may set additional timescales. Delay carries real risk: in W A Goold (Pearmak) Ltd v McConnell [1995] IRLR 516, the EAT confirmed an implied term that employers will reasonably and promptly give employees an opportunity to obtain redress of a grievance.
Who should investigate an employee grievance in a small business?
Someone with no personal involvement in the complaint and no stake in the outcome. In smaller businesses, that often rules out the obvious candidates, particularly where the grievance concerns a director or the founder. Where internal impartiality is difficult, an external HR consultant can act as investigator or hearing chair and help preserve a separate appeal stage inside the business.
Can an employee bring someone to a grievance hearing?
Yes, where the grievance meeting concerns a legal or contractual duty owed by the employer. Section 10 of the Employment Relations Act 1999 gives workers in that situation the right to be accompanied by a fellow worker, a trade union representative or a trade union official. In Toal v GB Oils Ltd [2013] UKEAT/0569/12, the EAT confirmed that an employer cannot reject an otherwise qualifying companion simply because it would prefer someone else. Acas says that if there is doubt about whether the legal right applies, allowing a companion is good practice.
What happens if an employer ignores the Acas grievance procedure?
The Acas Code of Practice on disciplinary and grievance procedures is a statutory code. Under section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992, an employment tribunal can increase an award in a relevant case by up to 25% where an employer has unreasonably failed to follow it, or reduce an award by up to 25% where the employee has. Poor process can therefore add significant cost to a claim regardless of the underlying facts.
Can a workplace grievance be resolved without a formal process?
Often, yes, and Acas encourages considering informal resolution or mediation where appropriate and where the employee is willing. Workplace mediation uses a neutral facilitator to help people rebuild a working relationship and can avoid a longer formal process. It will not suit every case. Serious allegations may require a formal investigation, particularly where facts need to be established or there are legal or safeguarding risks.