Grievance or whistleblowing disclosure: which process applies

A complaint arrives that does two things at once. It says a manager has made the writer's working life difficult, and it says the same manager has been making remarks of a sexual nature to a junior colleague.

The first half is a grievance and you know roughly what happens next. The second half may also be a whistleblowing disclosure, which brings its own rules about who investigates, what you can promise and how the person may be treated afterwards. This guide sets out how to tell the difference, what the second label adds, and how to run one process without breaking either set of rules.

As checked on 1 October 2026, whistleblowing protection sits in Part IVA of the Employment Rights Act 1996 and extends to England, Scotland and Wales. Since 6 April 2026 the matters a worker can blow the whistle about include sexual harassment, added by section 23 of the Employment Rights Act 2025 and brought into force by regulation 3(2) of SI 2026/323. Northern Ireland has its own framework and is not covered here.

Work out whether the complaint is also a disclosure

Two conditions decide it, and both sit in the opening words of section 43B(1). A qualifying disclosure is a disclosure of information which, in the reasonable belief of the worker making it, is made in the public interest and tends to show one or more of the listed failures. Section 43B, Employment Rights Act 1996.

GOV.UK words the list of failures this way: a criminal offence, for example fraud; someone's health and safety is in danger; risk or actual damage to the environment; a miscarriage of justice; the company is breaking the law, for example does not have the right insurance; you believe someone is covering up wrongdoing; and sexual harassment. GOV.UK on whistleblowing.

The two conditions govern every item on that list, including the newest one. A report of sexual harassment is therefore not automatically a disclosure. It has to convey information, which is what section 43B(1) asks for, rather than only ask for something to be done. The person also has to hold both beliefs: that what they describe tends to show sexual harassment, and that saying so is in the public interest. Sexual harassment here carries its Equality Act meaning of unwanted conduct of a sexual nature, which is narrower than treating someone badly because of their sex. Section 26(2), Equality Act 2010.

A qualifying disclosure becomes a protected one when it reaches a permitted recipient. A disclosure to you as the employer is the ordinary route, and among the least demanding: to be protected, the worker does not have to act in good faith, and does not have to be right. Section 43C, Employment Rights Act 1996. The higher test of reasonably believing the information is substantially true applies where a worker goes instead to a prescribed regulator. Section 43F, Employment Rights Act 1996.

Three questions get you to a working answer on the day it lands. Does it tell you something, as opposed to only asking you for something? Does it point beyond the writer's own treatment, to a risk to someone else or to the business breaking the law? Would a reasonable person in their position think it was worth the business knowing? Where the answers are yes, treat it as a disclosure and record that you did.

You are not the judge of this. Acas notes that a grievance can amount to a qualifying disclosure and that the worker should say so explicitly if they take that route. Acas on how to make a whistleblowing disclosure. Do not wait for them to say so. A tribunal decides the question afterwards, on what was written and what you did about it.

Check what the second label adds

Three things, none of which the grievance procedure by itself addresses.

The person must not be subjected to a detriment on the ground that they made the disclosure. Detriment covers an act or a deliberate failure to act. It also covers what a colleague does to them in the course of that colleague's employment, which is treated as done by you, unless you can show you took all reasonable steps to prevent it. Section 47B, Employment Rights Act 1996.

A dismissal for making a protected disclosure is automatically unfair, and no qualifying period of service applies to that claim. Section 108(1) sets the general two-year qualifying period for unfair dismissal, and subsection (3)(ff) takes whistleblowing dismissals out of it. Section 108, Employment Rights Act 1996. The general period is scheduled to fall to six months on 1 January 2027, which changes nothing here: for this claim there has never been a period to serve. Section 25, Employment Rights Act 2025; Commencement regulations, SI 2026/559. Our Employment Rights Act key dates page carries that timetable.

The cap on the compensatory award does not apply to a dismissal of this kind. Section 124, Employment Rights Act 1996. Section 25 of the 2025 Act is also scheduled to remove the cap for every unfair dismissal claim from 1 January 2027, so that difference is due to disappear then.

The grievance outcome is one decision made once. Detriment is a pattern built out of small decisions over the months that follow: who gets the overtime, who is left off the rota for the good shifts, whose training request goes unanswered. Whoever makes those decisions needs to know a disclosure was made, and needs to be able to show why each decision was made on its own merits.

Run one process with two sets of care

Acas says it is usually not good practice to make a qualifying disclosure through a grievance, because grievance procedures are not designed to address those concerns. Acas on how to make a whistleblowing disclosure. That is advice to the worker. Acas's advice to employers is to check with the person who raised the grievance. If they are making a disclosure as well, you might need to follow both procedures. Acas on responding to a whistleblowing disclosure.

The grievance half runs as it always does, through the Acas Code steps set out in our guide to handling a grievance under the Acas Code. Four things change around it.

Acknowledge in writing and say what you are treating as what. One paragraph is enough: this part is being handled as a grievance about your own treatment, this part is being looked into as a concern about someone else, under the whistleblowing policy where there is one, and here is who is doing each.

Acas says the person investigating should be impartial and trained for the role. Acas on handling a sexual harassment complaint. In a business of 10 to 49 people that usually means another director, a manager with no involvement in the subject matter, or an external HR adviser. Where you can, make that person someone other than the one who decides the outcome. Decide who it is before a complaint arrives rather than during one.

Promise the confidentiality you can actually keep. Acas says to keep the whistleblower's identity confidential and to reassure them that you will. Acas on responding to a whistleblowing disclosure. Against that, the person accused needs enough detail to answer the allegation. Where the detail identifies the source, say so at the start instead of discovering it halfway through. Acas also says not to move the person who complained unless they ask, because an unrequested move can look like a punishment. Acas on handling a sexual harassment complaint.

Report back in two registers. Acas says to keep the whistleblower informed of the progress of the investigation and to give feedback afterwards, explaining if action has been taken. Acas on responding to a whistleblowing disclosure. That is not the same as the grievance outcome letter. They should be told whether their own grievance was upheld. What disciplinary action a third person received is that person's information, and "action has been taken" is usually as far as you go.

Write the file so it can be read by the people in it

Both the person who complained and the person complained about can ask for the personal data you hold about them. The ICO deals with this case directly and states that you must balance the requester's right of access against the whistleblower's rights, weighing the requester's rights under the UK GDPR, the whistleblower's rights as a third party, and the whistleblower's protection under the Public Interest Disclosure Act 1998. Its worked example shows a report withheld by reference to exemptions covering crime and the identification of other people. ICO subject access request questions and answers for employers. That page carries a notice that the guidance is under review following the Data (Use and Access) Act, so check it before relying on it.

The practical consequence is a filing decision taken at the start. Keep the account that identifies the source in one place, with access limited to the investigator and the decision-maker, and keep the shareable working file separately. Record why you categorised the complaint as you did, and record the decisions taken afterwards about the person who raised it, with the reason for each. That second record is the one that answers a detriment allegation.

On how long to keep it, the tribunal clock rather than the grievance sets the period. Since 1 October 2026 the time limit for most tribunal claims has been six months rather than three, where the act complained of falls on or after that day. Commencement regulations, SI 2026/954. Breach of contract claims in Scotland are due to follow on 9 November 2026, under an order still in draft when checked on 1 October 2026. Government guidance on tribunal time limits. Draft Scotland order. Early conciliation extends the outside date further. Acas on employment tribunal time limits. Our guide to how long to keep leaver records works through the retention schedule that follows, and a whistleblowing file is a good reason to write one if you have not.

Do the three things the government page asks

The government's employer page on whistleblowing protections, last updated 30 July 2026, gives three actions: check the whistleblowing policy is up to date, brief managers on the updated protections, and communicate the changes to your workforce. Government guidance on whistleblowing protections.

The policy first. The government's guidance for employers says you are not legally required to have one. GOV.UK whistleblowing guidance for employers. Acas recommends one anyway: it says an organisation without a whistleblowing policy should put one in place as soon as possible, and sets out what it should cover. Acas on responding to a whistleblowing disclosure. Acas on having a whistleblowing policy. The government page assumes one exists and asks you to check it. Add sexual harassment to the list of matters it covers, name who a concern goes to and who the alternative is when the usual person is involved, and save the dated version. Point workers to the GOV.UK list of prescribed people and bodies for the external route rather than reproducing it. GOV.UK list of prescribed people and bodies.

Then the managers, in half an hour. The content is the one thing they will need: a complaint of this kind can carry protection from the first day of employment, so escalate it and change nothing about how the person is treated in the meantime. Keep the agenda and send a short note of what was agreed.

Then the workforce, in an email that says where the policy is and who to speak to.

This lands alongside the harassment duty. The timetable schedules three harassment measures for 30 October 2026. Two of them land on you directly: the duty to prevent sexual harassment becomes one to take all reasonable steps, and employers will be under an obligation not to permit harassment of their employees by third parties. The third is a power for the minister to make regulations later specifying evidence-based steps employers must take, which the page says will complement rather than replace the all reasonable steps requirement. The page states that all future dates remain subject to parliamentary processes and may change. Government implementation timetable. Our guide to preventing sexual harassment before 30 October covers the steps and the risk assessment. One overlap is useful. "All reasonable steps" is also the wording of the defence in section 47B where the detriment came from a colleague rather than from you, so the briefing and training records you build for one are the records you reach for in the other. Section 47B, Employment Rights Act 1996.

One item is enacted but has no date. Once in force, section 24 of the Employment Rights Act 2025 will make a term in an agreement with a worker void so far as it tries to stop them alleging or disclosing harassment or discrimination, unless the agreement meets conditions set by regulations. So far it is in force only to allow those regulations to be made. Section 24, Employment Rights Act 2025. The timetable lists the regulations under 2027, with no day given. What is already the position is that a confidentiality clause is not valid so far as it tries to stop a worker making a whistleblowing disclosure. GOV.UK on whistleblowing.

Seek appropriate advice early where a complaint alleges harassment or discrimination, where dismissal is one of the possible outcomes, or where you are deciding what to hold back from a subject access request.

Common questions

Is a grievance the same as a protected disclosure?

No, although one complaint can be both. A grievance is usually a complaint about the writer's own treatment. A qualifying disclosure is a disclosure of information which, in the reasonable belief of the worker, is made in the public interest and tends to show one of the failures listed in section 43B(1), and it becomes protected when it reaches a permitted recipient such as you. Section 43B, Employment Rights Act 1996. Acas says it is usually not good practice to make a qualifying disclosure through a grievance, because grievance procedures are not designed for those concerns, and that a worker taking that route should say so explicitly. Acas on how to make a whistleblowing disclosure.

Is a report of sexual harassment automatically a whistleblowing disclosure?

No. Since 6 April 2026 sexual harassment is one of the failures a disclosure can be about, added by section 23 of the Employment Rights Act 2025 and commenced by regulation 3(2) of SI 2026/323. The reasonable belief and public interest conditions in the opening words of section 43B(1) still have to be met, and they apply to that category as they do to every other. Section 43B, Employment Rights Act 1996. So a report of sexual harassment can be a protected disclosure rather than always being one.

Can you dismiss someone with under two years' service for whistleblowing?

A dismissal whose reason is that the employee made a protected disclosure is automatically unfair, and the two-year qualifying period in section 108(1) does not apply to that claim because subsection (3)(ff) takes it out. Section 108, Employment Rights Act 1996. The cap on the compensatory award also does not apply. Section 124, Employment Rights Act 1996. Seek appropriate advice before dismissing anyone who has raised a complaint of this kind.

Does a small business need a whistleblowing policy?

The government's guidance for employers says you are not legally required to have a whistleblowing policy. GOV.UK whistleblowing guidance for employers. Acas recommends one anyway: it says an organisation without a whistleblowing policy should put one in place as soon as possible. Acas on responding to a whistleblowing disclosure. The government's employer page assumes one exists and asks employers to check it is up to date, brief managers on the updated protections and communicate the changes to the workforce. Government guidance on whistleblowing protections.