TL;DR: Collective consultation bites when you propose 20 or more redundancies at one establishment within any rolling 90 days, and most costly mistakes happen in that scope test rather than in the timeline that follows. This guide walks the decision test, the 30 and 45-day floors, representative elections, the online-only HR1 form, and the two separate risks of getting it wrong: a protective award of up to 180 days' pay per employee, and a criminal offence that can reach directors personally.
The decision test: does collective consultation apply to you?
Before you look at a single timeline, answer three questions in order. How many dismissals are you proposing? Within which rolling 90-day period do they fall? At which establishment? All three have to line up before the collective duty bites, and most of the costly mistakes in a redundancy exercise are made here rather than in the consultation that follows.
The trigger itself is short. Under section 188 of the Trade Union and Labour Relations (Consolidation) Act 1992, an employer proposing to dismiss as redundant 20 or more employees at one establishment within a period of 90 days or less must consult appropriate representatives.
What counts towards the 20 is narrower than people assume. You are counting proposed redundancy dismissals; resignations, ordinary conduct dismissals and the retirement someone had already booked do not go into the total. Note the word "proposes" too: the test looks at what the employer proposes, not at what eventually happens. Propose 24, redeploy ten into vacancies elsewhere and dismiss 14, and the duty still applied from the moment 24 were proposed.
Two distinctions matter early. This duty is to consult representatives; individual consultation is a separate obligation running alongside it, and thorough one-to-ones do not discharge the collective duty. And collective consultation does not replace the ordinary requirements of a fair process: a flawless 45 days will not rescue a badly drawn selection pool, so have the full stage-by-stage redundancy process mapped before you start.
Counting the 90-day window in practice
The window is rolling: any period of 90 days or less, not a quarter aligned to your financial calendar. A tribunal asks whether 20 or more proposed dismissals fall inside some 90-day stretch, wherever it happens to sit.
Hence the most common structural error. Splitting a reduction of 23 roles into tranches of 12 in March and 11 in May does not take you out of scope if both sit inside the same 90 days: tribunals look at the substance of the proposal, not the packaging.
Here is where the law is genuinely less tidy. TULRCA does not define a precise triggering event for starting the count — the date the business case was signed off, the date representatives were informed, the date notice was given — and no primary source pins it down. The honest operating position is the one the statute supports: any rolling 90-day period in which 20 or more proposed dismissals fall. Do not over-specify internally either.
So if a second wave is foreseeable when you plan the first, plan on the basis that both count, and where the numbers are uncertain, consult as if you are in scope. Starting collectively and discovering you did not need to costs some time and some good faith; not starting and discovering you should have is uncorrectable once notice is served.
"One establishment": the question Woolworths settled
Establishment means the discrete local unit to which the affected employees are assigned to carry out their duties. It is not the whole organisation by default, and it is not automatically every individual site either.
That ambiguity sat at the centre of a mass claim after Woolworths collapsed: in USDAW and anor v WW Realisation 1 Ltd (in liquidation) and anor (Case C-80/14), decided by the CJEU on 30 April 2015, could employees at smaller stores be aggregated with the rest of the business, or did each store stand alone? As CMS's analysis of the case sets out, the answer was a local-unit test applied to the facts.
So neither shortcut is reliable. A single legal entity with three regional offices making eight redundancies at each site may well sit below the threshold, if those offices are genuinely distinct units with their own management and workforce. One head office proposing 22 redundancies is plainly in scope. The deciding factor is the unit, not the company.
This is the piece of the test most HR-sector content leaves out entirely, which is why "which establishment" is where readers most often receive a confident wrong answer. Since Brexit the ruling is persuasive authority on the meaning of establishment rather than binding EU law, but the local-unit approach remains the reference point.
The 30 and 45-day clocks are floors, not targets
Where 20 to 99 redundancies are proposed, consultation must begin at least 30 days before the first dismissal takes effect; where 100 or more are proposed, at least 45 days. Both sit in s188(1A) and both are confirmed on GOV.UK's consultation guidance.
The part most readers miss is the shape of the rule. Search for how long collective consultation takes and you get a single number back; the accurate answer is that there is a floor and no ceiling. Nor does the floor shorten because the conversation finished: if representatives have said everything they want to say by day 18, dismissals still cannot take effect before the period expires.
What the consultation must cover is set by s188(2), and it must be undertaken with a view to reaching agreement: ways of avoiding the dismissals, ways of reducing the numbers, and ways of mitigating the consequences for those who do go. A process designed only to relay a decision does not meet that standard.
Section 188(4) then sets out what you must disclose in writing to the representatives:
- the reasons for the proposals
- the numbers and descriptions of employees affected
- the proposed method of selecting who may be dismissed
- the proposed method of carrying out the dismissals, including the timetable
- the proposed method of calculating any redundancy payments beyond statutory entitlement
Look closely at the third item. The selection method has to be disclosed and then discussed, so it needs to be defensible before consultation opens rather than tidied up afterwards: building a selection matrix you can actually defend belongs to the preparation phase.
Electing employee representatives without losing days
Under s188(1B), consultation must be with appropriate representatives: the union's representatives where an independent trade union is recognised for the affected group, and otherwise employee representatives elected or appointed by the affected employees. Consulting the affected individuals directly is not an alternative, however thorough those meetings.
Acas's guidance on holding collective consultation sets out what makes an election fair:
- everyone affected can stand as a candidate
- everyone affected can vote
- the vote is secret
- the count is accurate
Where there are more candidates than seats, that secrecy means a ballot: candidates listed, votes cast privately, papers counted, result recorded.
Timing protects your plan. The election has to conclude before the 30 or 45-day clock can usefully start, because until then there is nobody to consult, so schedule the nomination window and the ballot as their own stage rather than letting them consume a week of the statutory period. Acas's guidance on when to begin is worth reading alongside your timeline.
Two situations fall outside the tidy version. When nobody volunteers, you cannot compel a candidacy: invite nominations properly, extend the window once, and record what you did before proceeding on the basis that the group declined. When a union is recognised for part of the affected group but not the rest, the interaction is not fully settled; the usual answer is a hybrid, union representatives for their constituency and elected representatives for the remainder. That is a point to take legal advice on rather than reason through in-house.
Representatives also need paid time off, somewhere to meet, access to the affected employees, and the s188(4) information early enough to read before the first meeting.
The HR1 form: online-only, and due before any notice
Separately from consulting anyone, section 193 requires advance notification to the Secretary of State on form HR1, handled in practice by the Insolvency Service's Redundancy Payments Service. The trigger is the same test: 20 or more proposed redundancies at one establishment within 90 days.
The timing mirrors the consultation floor — 30 days ahead for 20 to 99, 45 for 100 or more — and notification must always come before any notice of dismissal is given to anyone. That last clause catches people out when the commercial timetable starts outrunning the compliance one.
Since 1 December 2025, HR1 must be submitted online; paper and email are no longer accepted. That date rests on consistent reporting from employment law firms including Littler and Bates Wells rather than a dated commencement page, so treat it as settled practice rather than a statute you can cite.
The live submission service runs to eight parts, takes roughly 40 minutes, does not autosave, and times out after 90 minutes of inactivity. Gather everything before you open it: establishment details, the numbers and categories of employees affected, the proposed dates, and the representatives' details.
A copy of the HR1 should also go to the representatives — easily missed when finance or an external adviser files the form.
Two separate risks, enforced two separate ways
There are two risks here, and they are enforced separately. Breaching the consultation duty is a civil matter brought by or on behalf of employees. Failing to notify under s193 is a criminal offence. Most coverage folds the two into one paragraph headed "penalties", which loses that they run independently.
Risk one: the protective award. Under section 189, a tribunal can order the employer to pay remuneration for a protected period, with the length set according to the seriousness of the default. As of 6 April 2026, the maximum doubled from 90 days' pay to 180 days' pay per employee under the Employment Rights Act 2025, a change Lewis Silkin set out in their 15 October 2026 summary of the Act. A great deal of cached content and most AI-generated summaries still quote 90 days.
Run the arithmetic: a 40-person reduction at 180 days' gross pay each is a fundamentally different exposure from the same reduction at 90. And the award is not scaled down because the redundancies were genuinely necessary.
Risk two: the criminal offence. Section 194 makes failure to notify under s193 an offence triable on summary conviction, with liability extending beyond the company to directors, managers and similar officers where the failure happened with their consent or connivance, or was attributable to their neglect. In England and Wales, prosecution requires the Secretary of State's authorisation.
The fine is in practice unlimited: the old £5,000 cap on level 5 of the standard scale was removed in England and Wales by section 85 of the Legal Aid, Sentencing and Punishment of Offenders Act 2012, in force from 12 March 2015, as CMS Law-Now reported at the time. And this exposure exists whether or not a single employee ever brings a tribunal claim. An exercise that closed quietly, with everyone accepting their terms, can still have left an unfiled HR1 behind it.
Two edge cases HR teams keep hitting
Sickness absence during consultation. Being off sick does not remove an employee from the affected pool, and it does not pause your duty to consult them. Adjust how consultation is delivered rather than proceeding without them: remote meetings, written materials, longer periods to respond. Where the absence is disability-related, the Equality Act's protected characteristics and the reasonable-adjustment duty apply to the consultation process itself. Where someone is medically unable to engage at all, pausing that individual's strand with a supporting medical note is the defensible route.
No single statutory provision governs this fact pattern. It is assembled from the general reasonable-adjustment duty plus consistent practitioner guidance, which is why the instruction to a line manager is "adjust and document".
What is coming but is not yet law. The Employment Rights Act 2025 keeps the existing 20-at-one-establishment trigger and adds a parallel organisation-wide trigger, with either route sufficient to engage the duty — which matters most to multi-site employers currently below the threshold at every establishment. Do not act on a number, though, because there is not one yet: as Blake Morgan's analysis of the threshold change records, the figure was consulted on across a 250 to 1,000 range, the consultation closed on 12 May 2026, and implementation is expected in 2027.
Where to start if you are days from a decision
The test in one line: count the proposed dismissals, check the rolling 90 days, identify the establishment. Then the sequence:
- Confirm scope against the three-part test.
- Run the representative election, with the nomination and ballot window scheduled as their own stage.
- Open consultation with the s188(4) information supplied in writing.
- File the HR1 before any notice of dismissal is given, and send the representatives a copy.
- Keep a dated record of every meeting, every piece of information disclosed, and every alternative considered.
That record is what a tribunal reads when it sets the length of a protected period. One risk is measured in days of pay per employee, the other reaches individuals personally, and the paperwork is the main evidence in both.
These are also the processes where judgement and tone matter most, and the team's attention belongs on the conversation rather than the compliance trail. For the stages either side, see the full stage-by-stage redundancy process and a selection matrix you can actually defend.