Conduct and grievances · 5 min read

Handling grievances: from complaint to closed

Informal resolution, the formal grievance meeting, investigation, the outcome letter, appeals, overlapping disciplinary matters, grievances about the owner, and the victimisation trap.

Reviewed September 2026. Guidance, not legal advice: employment law moves, so check the current position before relying on any of it.

A grievance is a complaint by an employee about their work, their treatment or their colleagues. Handled well, it is how a small business finds out about a problem before it becomes a resignation or a claim. Handled badly, or not at all, it is the first exhibit in the claim, because a tribunal asks what the employer did when it was told.

This guide covers the informal stage, the formal process under the Acas Code, what to do when the grievance is about the boss, how grievances and disciplinaries interact, and the one rule that matters most: the complainant must not be treated worse for complaining.

Informal first, where it fits

Many grievances are a conversation: a rota clash, a misunderstanding with a colleague, a pay query. Encourage people to raise things with their manager, and managers to deal with them within days and confirm what was agreed by email. Serious matters (harassment, discrimination, safety, anything involving the manager themselves) go straight to the formal route, and an employee who asks for the formal route gets it.

The formal grievance

The employee puts the grievance in writing (or you write down what they said and ask them to confirm it). Acknowledge it within a couple of days, name who will hear it, and invite them to a meeting within a week or two. The person hearing it must not be the subject of the complaint, and should not be their close ally. At the meeting the employee explains the grievance, says what they want to happen, and can be accompanied by a colleague or trade union representative. Take notes; share them.

Investigate before deciding

Do not decide in the meeting. Go away, speak to the people named, look at the records, and where the grievance is about another employee's conduct, follow the disciplinary investigation route for that person in parallel. Keep the complainant informed of progress and timescales. If the grievance is about a policy or decision (a rota change, a pay rate), gather the reasoning and the evidence for it.

The outcome

In writing, point by point, in the employee's order: upheld, partly upheld or not upheld, with the reason and the evidence relied on, and the action that will follow with dates and owners. Where the action is disciplinary against someone else, say the matter has been addressed and that the details are confidential. Where a grievance is not upheld, say explicitly that raising it was right and will not be held against them. Offer an appeal.

The appeal

Heard by someone not previously involved, more senior where possible, within a couple of weeks. Each ground of appeal answered in writing. The appeal outcome closes the internal process and says so. It is the last chance to fix something the first decision missed, and it is cheaper than a claim.

Grievance about the owner or the only manager

In a business of eight people where the grievance is about the person who runs it, the honest answer is an external HR adviser or consultant to hear the grievance and recommend an outcome, with the owner accepting the recommendation. The employee has to believe the process was fair, and so does a tribunal; an owner hearing a grievance about themselves fails both tests.

Grievance during a disciplinary

Employees sometimes raise a grievance when a disciplinary process starts. The Code allows you to pause the disciplinary to deal with the grievance where they are related (the grievance is about the manager running the disciplinary, or about the fairness of the process), or to run both in parallel where they are not. Decide, record why, and tell the employee. Do not simply ignore the grievance because you suspect its timing.

Victimisation

Treating an employee worse because they raised a complaint about discrimination or harassment (or supported someone else's) is victimisation under the Equality Act, a claim in its own right with uncapped compensation, regardless of whether the original complaint succeeds. Cold-shouldering, a worse rota, being passed over, being disciplined for something that would otherwise have been ignored: all of it counts. After a grievance, watch how the complainant is treated, and document decisions that affect them.

The checklist

  1. A written grievance policy stating how to raise one and who hears it, referenced from the statement of particulars.
  2. Acknowledge within days; meeting within a week or two; person hearing it not involved in the complaint.
  3. Companion allowed; notes taken and shared.
  4. Investigate before deciding; keep the complainant informed.
  5. Outcome in writing, point by point, with actions and owners; reassurance where not upheld.
  6. Appeal by someone not previously involved; grounds answered; process closed.
  7. External adviser where the grievance is about the owner.
  8. Watch for victimisation afterwards; document decisions affecting the complainant.

What the law says

  • Acas Code of Practice on disciplinary and grievance procedures (2015), paragraphs 31 to 47.
  • Trade Union and Labour Relations (Consolidation) Act 1992 s.207A: the 25% adjustment for unreasonable failure to follow the Code.
  • Employment Relations Act 1999 s.10: the right to be accompanied.
  • Employment Rights Act 1996 s.3: the statement of particulars must say how to raise a grievance.
  • Equality Act 2010 s.27: victimisation; s.26: harassment; Worker Protection (Amendment of Equality Act 2010) Act 2023: the duty to take reasonable steps to prevent sexual harassment.

Questions people ask

Do I have to deal with a grievance from someone who has resigned?

You are not strictly required to, but you should, because a resignation followed by an unaddressed grievance is the shape of a constructive dismissal claim. Hear it, decide it, write the outcome. It costs a meeting.

Can I refuse to hear a grievance I think is malicious?

Hear it anyway. If the investigation shows it was raised in bad faith, that can be a disciplinary matter afterwards, but you need the investigation to show it. Refusing to hear it looks like avoidance and removes your best defence.

What if two employees have raised grievances about each other?

Hear both, separately, with the same person or two people who confer, and decide both on the evidence. Mediation, if both agree, often resolves what a formal outcome cannot. Do not pick a side before the process.

The admin this guide describes, done for you

Work-Lynx holds the records, calculates the entitlements, drafts the letters and reminds you of the dates: 49 UK policies, GPS clock-in, rotas, leave, timesheets, payslips and Employ AI for the questions in between. £2.50 a month plus £1 per employee, 14 days free, no card.

Start free trial