Most employers treat their grievance procedure as a page in the handbook that nobody reads until something goes wrong. The Employment Rights Act 2025, which received Royal Assent on 18 December 2025, changes that calculation. The Act does not rewrite the ACAS Code of Practice on Disciplinary and Grievance Procedures, but it sharply raises the cost of getting the process wrong, and several of its provisions bear directly on how complaints about harassment, sick pay and working patterns must now be handled. This guide explains what has already changed, what is coming into force in stages through 2026 and 2027, and how to update an ACAS-aligned procedure so it stands up when a complaint lands on your desk.
How the Employment Rights Act 2025 reshapes the grievance procedure
Strictly speaking, the Act contains no clause headed "grievances". What it does instead is alter the environment in which every grievance procedure operates. The headline reform is the reduction of the qualifying period for ordinary unfair dismissal from two years to six months, taking effect on 1 January 2027, alongside the abolition of the statutory cap on the compensatory award. A poorly handled complaint that sours into a dismissal will therefore expose employers far earlier in the employment relationship, and for far larger sums. Anyone with six months' service on 1 January 2027 gains protection immediately on that date, which pulls a large slice of your existing workforce into scope overnight.
Two further strands matter. Since 6 April 2026, workers who disclose sexual harassment enjoy explicit whistleblowing protection under section 23 of the Act, which changes the legal character of certain grievances the moment they are raised. And the government has confirmed that it will consult with Acas on allowing employees to raise collective grievances about workplace conduct. That reform is a longer-term project with no commencement date, so treat it as direction of travel rather than current law. The practical conclusion is the same either way: the written procedure you rely on today needs a careful pass, section by section.
Legal framework: the ACAS Code and the statutes behind it
The backbone remains unchanged. The ACAS Code of Practice on Disciplinary and Grievance Procedures, issued under section 199 of the Trade Union and Labour Relations (Consolidation) Act 1992, sets the minimum standard: a grievance put in writing, a meeting held without unreasonable delay, a considered written outcome, and a genuine right of appeal to someone not previously involved. The right to be accompanied by a colleague or trade union representative at the grievance meeting comes from section 10 of the Employment Relations Act 1999 and applies from day one of employment. None of this has been repealed.
The teeth sit in section 207A TULRCA 1992. Where an employer unreasonably fails to follow the Code, a tribunal can uplift any award in a relevant claim by up to 25 per cent; the same reduction applies against an employee who ignores it. The Employment Rights Act 2025 layers new obligations on top of this settled structure through phased commencement regulations, with tranches landing in April 2026 and further waves scheduled through 2027. Restrictions on confidentiality clauses covering harassment and discrimination under section 24 are being brought in through secondary legislation, so the void-NDA rule should still be framed as incoming rather than in force. For the official implementation timetable, the Acas overview of the Employment Rights Act 2025 is the reference point, updated as each commencement date is confirmed.
Why the six-month qualifying period raises the stakes
Consider how grievances actually end. A significant share of them precede a resignation or a dismissal, and until now employers could handle complaints from staff with under two years' service knowing that an ordinary unfair dismissal claim was off the table. From 1 January 2027 that comfort disappears. An employee hired in July 2026 will hold full protection by the commencement date, and every hire after that reaches protection at the six-month mark. The window in which a sloppy grievance process carries little tribunal risk is closing.
The removal of the compensation cap compounds the exposure. The compensatory award has been limited to the lower of 52 weeks' gross pay or a fixed statutory ceiling; from the same date, that ceiling goes. For senior or highly paid employees, an unfair dismissal that began life as a mishandled complaint could produce an award several times what the old regime allowed. Add the section 207A uplift of up to a quarter for ignoring the ACAS Code, and the arithmetic becomes uncomfortable quickly. Process discipline is now a financial control, not an HR nicety. Employers who currently resolve complaints from newer staff informally, without minutes or outcome letters, should use the remainder of 2026 to bring those cases inside the written procedure. The cheapest moment to fix a grievance process is before the first claim that tests it.
Harassment complaints, whistleblowing and confidentiality clauses
Grievances alleging sexual harassment now sit in a category of their own. Since section 23 came into force on 6 April 2026, a worker who discloses sexual harassment can qualify for whistleblowing protection, which means detrimental treatment linked to the complaint gives rise to a day-one claim with no qualifying period at all. Your procedure should flag these complaints for escalation the moment they arrive: a line manager quietly parking a harassment grievance is no longer a training issue but a litigation risk. The employer's proactive duty to prevent sexual harassment under the Worker Protection (Amendment of Equality Act 2010) Act 2023 already required preventive steps; the new protection sharpens what happens after a complaint is made.
Settlement of these grievances also needs care. The Act targets confidentiality clauses that silence victims of harassment and discrimination, and once the relevant regulations under section 24 take effect, offending clauses will be unenforceable. Blanket gagging wording in outcome agreements should be stripped out now rather than after the deadline. Confidentiality still has a legitimate place in business life, protecting genuine trade secrets and commercial information, and a properly scoped non-disclosure agreement built for UK law remains valid for exactly that purpose. What it can no longer do is double as a tool for burying misconduct.
Rewriting the written procedure, clause by clause
Start with scope. The procedure should state plainly who can raise a grievance, from the first day of employment, and confirm that raising one attracts no detriment. Then look at subject matter. Complaints about statutory sick pay will change character from 6 April 2026, when SSP becomes payable from the first day of sickness and the lower earnings limit disappears, so any wording that assumes waiting days is already out of date. Grievances about refused working patterns deserve similar attention, since a rejected statutory flexible working request is one of the most common triggers for a formal complaint, and the appeal route in your procedure needs to dovetail with the statutory request process rather than contradict it.
Next, timings. The Code requires meetings "without unreasonable delay", and the safest way to honour that is to commit to indicative timeframes in writing: acknowledgment within a few working days, a meeting within a defined window, an outcome letter shortly after, and an appeal heard by a more senior manager not previously involved. In practice, the appeal stage is where most procedures are weakest, because small employers run out of impartial managers. Name a fallback, such as a director or an external HR consultant, before you need one. Finally, make sure the grievance chapter of your ACAS-aligned employee handbook matches the standalone procedure word for word. Tribunals seize on discrepancies between documents that were supposed to say the same thing.
Updating your grievance documents with Captain.Legal
Rebuilding this paperwork from a blank page is slow work, and the risk of missing a statutory reference is real. The grievance procedure and response letter pack drafted to the ACAS Code on Captain.Legal covers the full sequence: the written procedure itself, the acknowledgment letter, the invitation to the grievance meeting with the section 10 accompaniment wording, the outcome letter and the appeal correspondence. You answer a short series of questions about your organisation, the size of your management structure and how you want appeals routed, and the platform assembles documents with the correct references to the ACAS Code, section 207A TULRCA 1992 and the Employment Relations Act 1999 already in place.
The output arrives in editable Word and clean PDF, so HR can adapt individual letters to the facts of each complaint while the underlying procedure stays fixed. Because the templates track legislative change, the phased commencement of the Employment Rights Act 2025 is reflected as each tranche takes effect, which spares you the job of monitoring commencement regulations yourself. For employers who prefer to overhaul everything at once, pairing the grievance pack with a matching disciplinary procedure and warning letter pack keeps both halves of the ACAS Code consistent in tone, timeframes and escalation routes.
Mistakes employers keep making
The most persistent error is treating an informal chat as a substitute for the formal process. Resolving matters informally is legitimate and the Code encourages it, but the moment an employee puts a complaint in writing, the formal machinery must engage, and a manager who replies "let's just talk it through" without ever issuing an outcome letter has handed the employee a section 207A uplift argument. Close behind comes the missing appeal. Employers frequently deliver a thorough investigation and a well-reasoned outcome, then forget to offer the right of appeal in the outcome letter, which reads to a tribunal as a procedure abandoned one step from the finish line.
Documentation failures round out the pattern. Meetings held without notes, witnesses interviewed without statements, and outcome decisions communicated verbally all dissolve under cross-examination two years later. A related trap is inconsistency: upholding one employee's complaint about a manager while dismissing an identical complaint from a colleague invites a discrimination angle that is far harder to defend than the original grievance. The last mistake is a 2027 problem arriving early. Some employers still run a two-track system, formal process for staff with two years' service and improvisation for everyone else. That distinction stops making sense on 1 January 2027, and the habits built now are the ones that will be tested then.
Frequently asked questions
Is a written grievance procedure legally required in the UK?
Not as a standalone statutory obligation, but the practical answer is yes. Under section 1 of the Employment Rights Act 1996, the written statement of particulars must tell employees how to raise a grievance and to whom. More importantly, the ACAS Code of Practice applies whenever a grievance is raised, and a tribunal can increase compensation by up to 25 per cent where an employer unreasonably fails to follow it. An employer without a written procedure will struggle to show it followed the Code. A short, clear document naming the responsible manager, the meeting stage and the appeal route is the minimum defensible position.
Has the Employment Rights Act 2025 replaced the ACAS Code?
No. The ACAS Code of Practice on Disciplinary and Grievance Procedures remains in force and remains the benchmark tribunals apply. What the Act changes is the surrounding law: whistleblowing protection for sexual harassment disclosures since 6 April 2026, a six-month qualifying period for unfair dismissal from 1 January 2027, the abolition of the compensation cap on the same date, and incoming restrictions on confidentiality clauses. Acas is also expected to update guidance as provisions commence, and the government has signalled a future consultation on collective grievances. Your procedure should be read against the Code first, then adjusted for each commencement date as it arrives.
How quickly must an employer respond to a grievance?
The Code sets no fixed number of days; the standard is "without unreasonable delay" at every stage. What counts as reasonable depends on the complexity of the complaint and the availability of witnesses, but tribunals expect an acknowledgment within days, a meeting within a week or two for straightforward matters, and an outcome letter promptly after any investigation concludes. Silence is the one response that is never defensible. If an investigation genuinely needs longer, write to the employee, explain why and give a revised date. A documented, explained delay rarely damages a case; an unexplained one almost always does.
What evidence should we gather during a grievance investigation?
Contemporaneous records decide these cases. Collect the written grievance, relevant emails and messages, rotas or pay records where the complaint touches them, and signed accounts from anyone with direct knowledge of the events. Interview witnesses separately, prepare a written summary of each account and have the witness confirm it. Where a dispute looks likely to escalate towards litigation, a properly structured witness statement template helps capture evidence in a form that holds its shape later. Keep the investigation file together and confidential, because the appeal manager and, potentially, a tribunal will read it end to end.
Do grievances about sick pay change under the new Act?
Yes, from 6 April 2026. Statutory sick pay becomes payable from the first day of sickness absence, removing the old waiting days, and the lower earnings limit no longer excludes low-paid workers. Complaints about unpaid or miscalculated SSP will therefore be tested against the new rules, and payroll decisions taken under the old regime wording will generate grievances if policies are not corrected. When refusing or adjusting sick pay, put the reasoning in writing using a compliant statutory sick pay decision letter, because a documented decision is far easier to defend at the grievance meeting than a verbal one.
Can an employee on probation raise a formal grievance?
Yes, and the procedure applies to them in full. The right to be accompanied under section 10 of the Employment Relations Act 1999 has no service requirement, and the ACAS Code draws no distinction between probationers and established staff. The change worth planning for is what happens afterwards: from 1 January 2027, an employee dismissed shortly after raising a grievance may claim ordinary unfair dismissal with only six months' service, and dismissals connected to protected disclosures or discrimination carry no qualifying period at all. Treating a probationer's complaint casually because "they can't claim anyway" is advice that has already expired.
What format should the updated procedure and letters take, Word or PDF?
Both, used for different jobs. The master grievance procedure works best as a PDF, circulated to staff and referenced in the handbook, because a fixed format prevents accidental edits to a document that must stay consistent across the workforce. The individual letters, acknowledgments, meeting invitations, outcomes and appeal responses, belong in editable Word, since each one must be tailored to the complaint, the dates and the people involved. Captain.Legal supplies every document in the grievance pack in both formats, so the procedure stays stable while the correspondence flexes case by case.