Grievance Procedure UK: The Employer's Step-by-Step Guide 2026

A kitchen manager at a Manchester restaurant arrived one morning to find a letter on his desk. One of his chefs had submitted a formal grievance, alleging unfair treatment over shift allocation. He had no procedure, no acknowledgement template and no idea whether he had to hold a meeting. By the time he eventually responded, two weeks had passed with no written word to the chef. The tribunal later awarded a 20% uplift on the final settlement for failure to follow the Acas Code.

That is what a missing or ignored procedure costs in practice. This guide walks through the correct process, step by step, so you know exactly what to do from the moment a formal grievance lands.

This is a step by step grievance procedure from the employer side. It follows the Acas Code of Practice on Disciplinary and Grievance Procedures, which tribunals use to judge whether you behaved reasonably. Get it right and you cap your risk. Get it wrong and tribunals can increase compensation by up to 25% for unreasonable failure to follow the Code.

What is a grievance and why the procedure matters

A grievance is a formal written complaint from an employee that triggers a mandatory procedure under the Acas Code of Practice. UK employers must acknowledge it within 5 working days, investigate, hold a meeting where the employee has the right to be accompanied, issue a written outcome and offer a right of appeal. Failing to follow the Code exposes employers to a 25% increase on any tribunal award.

A grievance is a concern, problem or complaint that an employee raises with their employer. It covers everything from a pay dispute to bullying allegations, rota changes to whistleblowing disclosures.

The legal backbone is Section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992, which gives the Acas Code its teeth. Tribunals must take the Code into account and can adjust awards by up to 25% either way for unreasonable failure to follow it.

Beyond the legal exposure, a well run procedure:

• Catches problems before they become constructive dismissal claims
• Creates a paper trail if matters escalate
• Signals to the workforce that complaints are taken seriously
• Often resolves the issue at stage one without any formal meeting

When the grievance procedure applies

Your written procedure should cover any concern not suitable for an informal chat. Typical examples:

• Pay, hours, holiday or contractual terms
• Working conditions and health and safety
• Bullying, harassment or discrimination
• Relationships with managers or colleagues
• Reorganisation or changes to working patterns
• Equality Act issues including reasonable adjustments
• Whistleblowing under the Public Interest Disclosure Act 1998

From April 2026, under the Employment Rights Act 2025, sexual harassment became a qualifying whistleblowing disclosure under the Public Interest Disclosure Act 1998. This means a worker raising a sexual harassment complaint via your grievance procedure may simultaneously have whistleblower status and cannot be subjected to detriment. See the whistleblowing policy guide and sexual harassment employer duty guide for how these protections interact.

The 5 steps of a grievance procedure

The Acas Code boils down to five core stages. Your written policy should mirror these steps with your own timelines and named roles.

| Stage | What you must do | Target timeframe | |-------|-----------------|-----------------| | 1. Acknowledge | Written confirmation of receipt, investigator name and next steps | Within 5 working days | | 2. Investigate | Witness interviews, document review, fact gathering | 1 to 3 weeks | | 3. Hold the meeting | Employee presents case, companion permitted | Within 2 to 3 weeks of receipt | | 4. Issue outcome | Written decision with reasons and appeal rights | Within 5 to 10 working days of meeting | | 5. Hear the appeal | More senior manager, review or rehearing | Within 2 to 3 weeks of appeal letter |

Work through each stage in order. Skipping steps is the single most common reason tribunals find against employers on procedural grounds.

Stage 1: Try informal resolution first

Most workplace issues are better fixed with a conversation. Line managers should be trained to listen, ask what outcome the employee wants and try to resolve it on the spot.

Informal resolution is not brushing it under the carpet. Document the conversation, note what was agreed and follow up in writing. If the issue is serious (harassment, discrimination, whistleblowing), skip informal and go formal.

Do not force an employee to try informal resolution before a formal grievance. The Code requires you to deal with grievances formally when raised formally.

Stage 2: Receiving a formal grievance

A formal grievance must be in writing. Your policy should set out where to send it: usually to the line manager, or to HR if the grievance is about the line manager.

Acknowledge the grievance in writing within 5 working days. Confirm:

• That you have received it
• Who will be investigating
• Approximate timeline to a meeting
• The employee's right to be accompanied at any grievance meeting

Do not investigate in silence. Employees who hear nothing assume the worst and often escalate to solicitors before you have even read the letter.

Choose the right decision maker

The person hearing the grievance should be senior enough to make binding decisions and independent enough to be objective. Never have someone investigate a grievance about themselves. For small employers with no alternative, bring in an external HR consultant.

You will need a separate, more senior person to hear any appeal. Plan this in advance.

Stage 3: Investigate properly

The investigation gathers facts. The meeting gives the employee a chance to explain their case and hear your preliminary findings. They are not the same thing.

Investigation steps:

• Interview the employee who raised the grievance
• Interview any named witnesses
• Review relevant documents: contracts, emails, rotas, CCTV, performance records
• Check policy against practice
• Keep contemporaneous notes of every interview

Witnesses should be told their account will be shared with the complainant unless there is a genuine risk of victimisation. Anonymous witness statements are a tribunal red flag.

Stage 4: Hold the grievance meeting

The grievance meeting is where the employee states their case in person, with the investigating manager present.

Timing

Hold the meeting "without unreasonable delay". Two to three weeks from receipt is a reasonable benchmark. Complex cases may justify longer, but communicate the delay in writing with reasons.

Right to be accompanied

Under Section 10 of the Employment Relations Act 1999, every worker has a statutory right to be accompanied by a trade union representative or a fellow worker. Postpone by up to five working days if the chosen companion cannot attend. See our right to be accompanied guide for detail.

How to run the meeting

• Introduce everyone and explain the format
• Invite the employee to set out their grievance in their own words
• Ask clarifying questions; do not cross examine
• Allow the companion to sum up and speak on the employee's behalf, but not to answer questions for them
• Summarise the points raised and confirm next steps
• Adjourn if new information needs further investigation

Take detailed notes and offer the employee a copy for corrections on factual points.

Stage 5: The written outcome

Communicate the decision in writing, usually within 5 to 10 working days of the meeting. The outcome letter should cover:

• A summary of the grievance raised
• The investigation steps taken
• The findings on each specific complaint
• The decision: grievance upheld, partially upheld, or not upheld
• Any actions to be taken (training, mediation, policy change, apology)
• The right of appeal, including who to appeal to and the deadline (typically 5 to 7 working days)

Avoid vague conclusions like "matters have been addressed". Tribunals want to see that you reached a reasoned decision on each specific point raised.

Stage 6: The appeal

Hear the appeal at a more senior level. This is the last internal chance to fix a flawed decision before a tribunal claim.

Two formats are acceptable:

• Review appeal: the appeal manager reviews the existing evidence
• Rehearing: the entire grievance is heard afresh with new fact finding

The rehearing format is safer where the original procedure was flawed. A rehearing can cure procedural defects. A review cannot.

The employee retains the right to be accompanied at the appeal meeting. Confirm the outcome in writing and state clearly that this is the final stage of the internal procedure.

Grievance procedure timeline at a glance

| Stage | Action | Target Timeframe | |-------|--------|-----------------| | Written grievance received | Log and assign an investigating manager | Day 0 | | Acknowledgement | Written confirmation of receipt, investigator name and next steps | Within 5 working days | | Investigation | Witness interviews, document review, fact gathering | 1 to 3 weeks | | Grievance meeting | Employee presents case; companion permitted | Within 2 to 3 weeks of receipt | | Written outcome | Decision on each complaint, with reasons and appeal rights | Within 5 to 10 working days of meeting | | Appeal heard | More senior manager; review or rehearing format | Within 2 to 3 weeks of appeal letter | | Appeal outcome | Final written decision; confirm end of internal process | Within 5 to 10 working days of appeal |

These are not statutory timelines. They are reasonable benchmarks tribunals recognise as compliant with the Code.

Special cases employers trip up on

Grievances raised during disciplinary action

Employees often raise a grievance as a defensive tactic when they are in a disciplinary process. The Acas Code allows you to:

• Pause the disciplinary and deal with the grievance separately, or
• Deal with both concurrently if they are related

Whichever route you choose, document it. If you run concurrent procedures, make sure different people hear each one. For the companion disciplinary side of this, see our disciplinary procedure employer guide.

Can an employee raise a grievance after resigning?

Yes. A post-resignation grievance is still a grievance. Handle it through the normal procedure, even if the employee has already left. Failing to do so is a classic trigger for constructive dismissal claims and is almost always cited in the tribunal pleading.

This applies whether the grievance arrives during the notice period or weeks after the leaving date. Run the full procedure: acknowledge in writing, investigate, hold a meeting (in person or by video call), issue a written outcome and offer an appeal. See constructive dismissal: an employer guide for how resignation and grievance interact.

Collective grievances

Where multiple employees raise the same grievance, allow them to raise it jointly through a spokesperson. Investigate once, meet the spokesperson and issue one outcome, with a copy for each employee.

Anonymous grievances

Anonymous complaints are not grievances under the Code because the procedure is designed for a named employee. Still assess whether they warrant a separate management investigation, particularly around safeguarding, financial or harassment concerns.

Grievances about harassment

Since October 2024, employers have had a proactive duty under the Worker Protection Act to prevent sexual harassment. From April 2026, the Employment Rights Act 2025 made sexual harassment a qualifying whistleblowing disclosure. Handle these with particular care. Confidentiality, speed and a clear paper trail matter more than in standard cases. See our sexual harassment employer duty guide for the full obligations.

Common grievance procedure mistakes

The patterns that appear most often in tribunal claims:

• No written procedure or a procedure that nobody inside the business has read
• Line manager investigates a grievance about themselves
• No acknowledgement letter and weeks of silence before the first meeting
• Failure to offer the right to be accompanied in writing
• Outcome letter with no reasons, just a bare decision
• No appeal option or the same person hearing the appeal as the original grievance
• Concurrent disciplinary and grievance handled by the same manager
• Witness evidence taken but never shared with the complainant
• Ignoring grievances from people on sick leave

Each of these has led to tribunal awards being uplifted by 25%.

What to put in your written policy

Your written grievance policy should include:

• Purpose and scope
• Who to submit the grievance to, with a backup if that person is the subject
• Target timelines for each stage
• The right to be accompanied
• How the investigation will be conducted
• Decision making authority at each stage
• Appeal rights and deadline
• Confidentiality expectations
• Record retention (usually 6 years)
• Links to related policies: disciplinary, whistleblowing, bullying and harassment

Every employee should have access from day one. Put a copy in the staff handbook and reference it in the written statement of particulars issued to every new starter.

Records and retention

Keep the following for at least six years after the grievance closes: the original grievance, acknowledgement letter, investigation notes, witness statements, documents reviewed, meeting notes, outcome and appeal letters, and evidence that agreed actions were completed.

Store them securely. Grievance records are special category personal data if they touch on health, sexuality, religion or race. Process them under your GDPR records of processing activity.

What the Employment Rights Act 2025 changes for employers

Picture this. It is October 2026. A care worker at a home care agency in Leeds has been on a zero-hours contract for 14 months. She has worked a predictable 30-hour week for the past 12. She submits a written grievance because her employer told her they were not offering guaranteed hours yet and gave no clear reason why. Her manager, under pressure to keep costs flexible, dismisses the grievance at the meeting. What he does not know: the rules changed in Autumn 2026, and she now has a statutory right to request those guaranteed hours. The grievance is not just a complaint. It is the opening move in a claim.

This is the world the Employment Rights Act 2025 creates. The Act does not rewrite the grievance procedure step by step. What it does is expand the categories of workers who are protected when they raise one, and add new substantive rights that generate entirely new types of grievances. Three changes matter most.

(a) Sexual harassment as a whistleblowing disclosure (from April 2026)

The Act amends the Public Interest Disclosure Act 1998 to make sexual harassment a qualifying disclosure. That means a grievance raising sexual harassment now carries simultaneous whistleblower protection.

The practical effect is significant. If an employee raises a grievance about sexual harassment and is then dismissed or suffers any detriment, they can bring both a harassment claim and a whistleblowing detriment claim. Whistleblowing claims have no qualifying period and no compensation cap. A dismissal that might have been an unfair dismissal claim with a statutory cap becomes an uncapped detriment claim on top of an uncapped harassment claim.

The right response is not just to process the grievance correctly but to ensure no adverse action is taken against the employee after the grievance is raised. Review any management decisions affecting that person during and after the procedure. A redundancy, a change to shifts, or a performance plan introduced in the weeks after a sexual harassment grievance is received will attract scrutiny.

(b) Zero-hours workers gaining guaranteed-hours rights (from Autumn 2026)

Workers on zero-hours or variable-hours contracts who have completed 12 weeks with a predictable working pattern gain the right to request a guaranteed-hours contract reflecting that pattern. Employers must engage with that request. They cannot simply ignore it or offer something obviously unsuitable.

This creates a new category of grievances. Workers can raise a grievance about:

• Whether their employer correctly calculated 12 weeks of qualifying work
• Whether the offer made genuinely reflects their actual working pattern
• Whether a refusal to offer guaranteed hours was reasonable

These are factual disputes. Keep records of hours worked week by week. If you are refusing or modifying a guaranteed-hours request, document the business reason clearly. A grievance file with no documented rationale for the decision is very hard to defend.

(c) Day-one unfair dismissal rights removing the two-year qualifying period (from 2027)

Currently, an employee needs two years of continuous service before they can bring an unfair dismissal claim. From 2027, that qualifying period goes. Every employee, from their first week, can raise a grievance and, if dismissed in connection with raising it, bring an unfair dismissal claim.

The option to manage an employee out before their rights accrued disappears entirely. An employer who dismisses a three-month employee the week after receiving a formal grievance from them will face a straightforward unfair dismissal claim, with no qualifying period defence available. Probationary period processes will need to be as documented and defensible as any other dismissal.

Review your written grievance procedure against all three timelines. The Employment Rights Act 2025 employer guide covers all 14 changes. If day-one unfair dismissal concerns you, the day-one unfair dismissal rights guide runs through what the 2027 change means for probationary periods and exit strategies.

What happens if the grievance becomes a tribunal claim

If the employee brings a tribunal claim, the grievance procedure is the first thing the tribunal will scrutinise. Expect the employee's legal representatives to issue a data subject access request for every document, note and email. Anything you did not share at the time can still be compelled later.

Write everything as though it will land in front of a tribunal judge. Dry, factual, dated. Avoid speculation or character judgements in emails. For the full tribunal path, see our employment tribunal process employer guide.

Grievance procedure checklist

• Written grievance received and logged
• Acknowledgement letter sent within 5 working days
• Independent investigating manager appointed
• Witnesses interviewed and notes retained
• Grievance meeting arranged with at least 5 days notice
• Right to be accompanied confirmed in writing
• Meeting notes offered to the employee
• Written outcome issued with reasons and appeal rights
• Appeal manager identified and briefed
• All records stored securely for 6 years

FAQs

Q: How long does an employer have to respond to a formal grievance in the UK?

A: There is no statutory deadline, but the Acas Code requires employers to respond "without unreasonable delay". Best practice is a written acknowledgement within 5 working days, a grievance meeting within 2 to 3 weeks and a written outcome within 5 to 10 working days of the meeting. Appeals should be heard within 2 to 3 weeks of the appeal letter. Exceeding these benchmarks without a clear reason exposes you to a 25% tribunal uplift for failing to follow the Code.

Q: Can an employee raise a grievance after they have resigned?

A: Yes. A grievance from a former employee, including one raised during their notice period or after their leaving date, should be handled under your normal procedure. Refusing to hear a post-resignation grievance is a frequent trigger for constructive dismissal claims and will almost always be cited in the tribunal pleading. Run the full procedure, including the appeal stage.

Q: Who can accompany an employee at a grievance meeting?

A: Under Section 10 of the Employment Relations Act 1999, a worker has a statutory right to be accompanied by a trade union representative (or certified union official) or a fellow worker. You cannot unreasonably refuse the chosen companion. If the first choice of companion cannot attend, the worker can propose an alternative, and you must postpone by up to 5 working days. Family members, solicitors or external HR consultants are not statutory companions, although you can permit them as a matter of policy.

Q: What happens if an employer ignores a grievance?

A: The employee can resign and claim constructive unfair dismissal on the basis that the failure to deal with their grievance was a fundamental breach of the implied term of trust and confidence. They can also bring substantive tribunal claims (for example on discrimination or unlawful deduction of wages) with a compensation uplift of up to 25% for your failure to follow the Acas Code. Ignoring grievances is one of the most expensive procedural failings an employer can make.

Q: Do we have to follow the Acas Code of Practice on grievances?

A: The Acas Code itself is not legally binding, but under Section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992, tribunals must take it into account. Tribunals can adjust compensation by up to 25% either way for unreasonable failure to comply. In practice, every UK employer should treat it as mandatory baseline.

Q: Can we have both a disciplinary and grievance process running at the same time?

A: Yes. The Acas Code allows concurrent handling where the issues are related, or pausing the disciplinary until the grievance is resolved where they are separate. Whichever route you take, use different managers for each process and document the decision. Running both with the same decision maker almost always leads to a procedural challenge at tribunal.

Q: Does the Employment Rights Act 2025 change how we handle grievances?

A: The Act does not rewrite the procedure itself, but it changes who is protected and what they can claim when they raise one. From April 2026, a grievance about sexual harassment carries simultaneous whistleblower protection under PIDA 1998, meaning any subsequent dismissal or detriment can attract an uncapped claim. From Autumn 2026, zero-hours workers gain the right to request guaranteed hours, opening a new category of disputes. From 2027, day-one unfair dismissal rights mean any employee dismissed after raising a grievance can bring a claim from their first week of employment.

Next steps

For all disciplinary and grievance guidance in one place, visit the Disciplinary & Grievance topic hub.

For a full review of your grievance procedure against the Acas Code, the Employment Rights Act 2025 changes and your actual practice, run the EmployerKit audit. It gives you a scored report on every part of your HR policy stack, with the exact wording and template updates you need to stay compliant.

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Sources and further reading

Official guidance and legislation referenced in this guide:

• Acas Code of Practice on disciplinary and grievance procedures
• Grievance procedure step by step (Acas)
• Raise a grievance at work (GOV.UK)
• Employment Relations Act 1999, Section 10
• Public Interest Disclosure Act 1998
• Employment Rights Act 2025