1. Acknowledge it properly and fast
Confirm receipt in writing, name who will handle it, and give a realistic timescale. Delay is the single most common complaint in grievance cases and the easiest thing to fix.
Check whether the person handling it is genuinely impartial. Someone in the same reporting line as the complaint is not.
2. Offer an informal route where it fits
Acas guidance encourages employers to resolve issues informally before formal procedures. Interpersonal conflict, communication breakdowns and management-style complaints often resolve faster and better through a facilitated conversation than through an investigation.
Some grievances should never be routed informally: allegations of harassment, discrimination, bullying, safeguarding concerns or anything that could amount to misconduct. Those go straight to the formal process.
3. Use mediation as a real option, not a delay
Mediation works when both parties enter it voluntarily and there is an ongoing working relationship worth repairing. It is not a way of parking a complaint or persuading someone to drop it, and framing it that way is what makes it backfire.
Record that mediation was offered, whether it was accepted, and what came out of it. That record is often the clearest evidence that the employer acted reasonably.
4. If it becomes formal, follow your own procedure exactly
Investigate proportionately, hold a grievance meeting, tell the employee of their right to be accompanied by a colleague or trade union representative, give the outcome in writing with reasons, and offer a right of appeal to someone not previously involved.
Departing from your own written procedure is one of the most reliable ways to lose a case you would otherwise have won.
5. Write it down while it is happening
Contemporaneous notes carry weight; reconstructed accounts written months later do not. Note dates, who was present, what was said, what was agreed and what happens next.
Keep the record factual and specific. Avoid conclusions and labels — describe what was observed, not what you inferred from it.
6. Close the loop
Check back weeks later. A grievance that was formally resolved but practically unchanged tends to come back, and the second time it arrives it is usually accompanied by a resignation or a claim.
Frequently asked questions
Can we insist an employee tries mediation before raising a formal grievance?
No. Mediation only works when it is voluntary, and requiring it before a formal grievance can be read as obstructing the employee's right to use the procedure. Offer it, explain it, and accept a refusal without penalty.
How quickly should a grievance be dealt with?
Acas expects grievances to be handled without unreasonable delay. Most procedures aim to hold a grievance meeting within a small number of working days of receiving the complaint, and to give an outcome shortly afterwards.
Does the employee have the right to be accompanied?
At a formal grievance meeting, yes — by a colleague or a trade union representative. Tell them this in writing before the meeting rather than assuming they know.
What if the grievance is about the employee's own manager?
Reassign it. The grievance must be heard by someone with no involvement in the events complained of, and the appeal by someone different again.
Do we have to give a right of appeal?
It is expected practice under the Acas Code, and failing to offer one is a common reason for a finding of unfairness even where the underlying decision was sound.
This is general guidance on UK workplace practice, not legal advice. If a case is contested, high-risk, or involves discrimination, ill-health or long service, take advice from a solicitor or ACAS before acting.
Next step
GoMediation.ai gives HR a confidential, structured route for grievances and workplace conflict — offered informally, recorded properly, and ready to hand over if it later becomes formal.
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