How long do I have to respond to a grievance?

Alan Creevy, Founder · 5th November 2026

Most employers asking this are looking for the statutory deadline. There isn’t one, and that is exactly why they get caught out. Three things operate in its place: a standard you will be measured against after the event, a single number Acas attaches to one step of the process, and a deadline you may well have set for yourself without realising it. The third is the one that does the damage.

The only hard deadline is usually one you wrote yourself

Before you reply to the employee, go and read your own grievance procedure.

Section 3 of the Employment Rights Act 1996 requires the written statement you give your staff to name a person they can apply to “for the purpose of seeking redress of any grievance relating to his employment, and the manner in which any such application should be made”, and to explain any further steps that follow. There is no exemption for small employers, so you almost certainly have a procedure somewhere, whether you wrote it, inherited it from a template, or had it drafted when you took on your first employee.

If that document says you will acknowledge a grievance within five working days and hold a meeting within ten, that is now the yardstick. A tribunal looking at how you handled it will start from what you told your staff you would do, not from whether ten working days was generous. Plenty of small employers have a handbook in a shared drive promising timescales nobody has read in three years, and the first person to read it closely is a solicitor.

If the timescales in it are unrealistic for a business of your size, fix that properly later by changing the document and telling staff. It is not a reason to ignore it this week.

What Acas actually puts a number on

One number, in one place. Acas guidance on the grievance meeting says the employer should hold the meeting without unreasonable delay, “ideally within 5 working days”.

Everything else is a standard rather than a deadline. The Acas Code of Practice on disciplinary and grievance procedures says at paragraph 4 that employers and employees “should raise and deal with issues promptly and should not unreasonably delay meetings, decisions or confirmation of those decisions”. Paragraph 33 asks for the formal meeting “without unreasonable delay”, paragraph 40 for the decision in writing, and paragraphs 42 and 45 the same for hearing an appeal and giving its outcome.

Notice what is missing. There is no Acas number for acknowledging the grievance, none for the written outcome, and none for the appeal window. Those are yours to set. Five working days from the invitation to the meeting, three from the meeting to a written outcome and five for the employee to appeal is a defensible rhythm, and the free timetable works the dates out around weekends.

Acknowledge it the same day

Acknowledgement is not the response. It costs ten minutes and buys most of the goodwill available in this process.

Reply the day it arrives, or the next working day if it landed at eleven at night. Confirm you have received it, say you are treating it as a formal grievance, name who will deal with it, and give the date you expect to hold the meeting. That last part stops the employee filling the silence with their own conclusions about whether you are taking it seriously.

What you must not do is engage with the substance. No early view on whether they have a point, no explanation of your side, no asking them to reconsider. If the grievance is about you, settle who is handling it instead, which the article on a grievance raised about you covers.

When you cannot hit the date, say so in writing

This is the part that separates a defensible file from an indefensible one, and almost nobody does it.

Grievances slip. A witness goes on holiday, the employee is signed off sick, the complaint needs an investigation you had not anticipated. Drift is not the problem. Silent drift is. Acas is explicit: if there are delays, “the employer should explain how long the delays will be and why”.

So when the date you gave is going to pass, write to the employee before it passes. One short message naming the new date and the reason. Three of those over six weeks reads as a process being managed. Six weeks of silence, then an outcome, reads as a business that hoped the complaint would go away, and that is how it will be characterised later.

Keep every one of those messages. A grievance that took nine weeks with four dated updates explaining why is a very different document to a grievance that took nine weeks.

What the delay actually costs

Three things, and they have all got more expensive recently.

First, if a claim reaches a tribunal on a matter the Code covers, section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992 lets the tribunal increase the award by up to 25% where the employer failed to comply with the Code and that failure was unreasonable. In unfair dismissal the uplift applies to the compensatory award rather than to everything, under section 124A of the Employment Rights Act 1996. Unreasonable delay is among the easier failures for an employee to evidence, because the dates sit in your own correspondence.

Second, Acas lists “raising a grievance that the employer refuses to look into” among the examples of conduct that can lead to a constructive dismissal claim. That example is about refusing, not about being slow, so do not read it as saying any delay is a resignation waiting to happen. It does show you where the line sits.

Third, the window has got longer. Most employment tribunal time limits rose from three months to six on 1st October 2026, under section 152 of the Employment Rights Act 2025, where the relevant date falls on or after that day. A grievance you let run for four months is now far more likely to still be inside the period in which a claim can arrive.

And from 1st January 2027 the qualifying period for unfair dismissal falls from two years to six months, with the cap on the compensatory award removed, which is covered in the article on the January change. A badly handled grievance from someone eight months into the job is about to carry risk it does not carry today.

Where employers go wrong in the other direction

Speed is not the whole virtue. A grievance answered in four days with no investigation worth the name is weaker than one answered in four weeks with a proper one.

The test is not how fast you were. It is whether the time you took was explained and was proportionate to what you were looking into. A straightforward complaint about a rota should not take a month. An allegation of bullying with four witnesses reasonably might, and a long grievance citing legislation does not become urgent just because it is long, which the article on grievances written with AI goes into.

What to do this week

Open your handbook or contract and find the grievance timescales you have already committed to. If there are none, your position is better than you think, because the Code’s standard of promptness is more forgiving than a specific number you have missed.

Acknowledge the grievance today in writing, with a named person and a meeting date. Put the meeting in the diary within about five working days, and if that is impossible, put it in the diary anyway and write to the employee explaining the new date. Allow three working days from the meeting to a written outcome, and tell the employee they have five working days to appeal, because they will not know unless you say so.

Then keep the dates. Not because a law says you must, but because the dates are the one part of this that a tribunal can check without hearing a word about who was right.

Tarn.hr provides HR guidance based on UK employment law and Acas codes of practice. It does not constitute legal advice and should not be relied upon as such. Employment law is complex and turns on the facts of each case. For any situation involving significant legal risk, potential tribunal claims, or matters of particular sensitivity, you should seek advice from a qualified employment solicitor. Tarn.hr is not responsible for any decisions made on the basis of its guidance.