UK business owners find out what collective redundancy UK law requires at the worst possible moment: when it is too late to fix. The HR1 form is not filed. Consultation has not started. The first dismissal notices are two weeks away. At that point, the business has committed a criminal offence and exposed itself to a Protective Award of up to 180 days' gross pay for every affected employee, with no cap. 

This is not a process that only large employers need to understand. Any UK business making 20 or more redundancies at a single site within 90 days is subject to collective consultation obligations. That threshold catches SMEs making one round of significant cuts just as easily as it catches multinationals. 

This guide walks through what collective consultation requires, how the collective consultation timeline UK law sets out works in practice, what the HR1 form does and when to file it, and the mistakes that turn a legitimate redundancy into an expensive and avoidable tribunal claim. 

What triggers collective redundancy, and where SMEs get the count wrong 

The obligation to follow collective redundancy procedures kicks in under section 188 of the Trade Union and Labour Relations (Consolidation) Act 1992 (TULRCA) when an employer proposes to dismiss 20 or more employees at one establishment within any 90-day rolling window. Two parts of that sentence trip businesses up more than any other. 

The first is the word 'proposes'. The duty to consult arises when the business is contemplating redundancies, not after it has decided on them. If the directors have a board meeting to agree in principle that 25 roles need to go, the collective consultation clock is already running. Informing employees of a decision already made is not consultation. Tribunals are consistent on this point, and the Protective Award exists precisely to penalise employers who skip the process or go through the motions after the outcome is fixed. 

The second is 'one establishment'. This does not mean the whole company. It means the physical location or operational unit where the affected employees work. A business with three depots making eight redundancies at each has not triggered collective consultation. A business closing one depot and making 24 people redundant there has, regardless of how many people it employs in total. The size of the headcount across the group is irrelevant. What matters is the number at that site, in that 90-day window. 

This catches SMEs when they plan a restructure across multiple sites and assume the numbers at each location stay below the threshold. If the reality of the working relationship means those employees are all part of one operational unit, a tribunal may treat them as one establishment. The test is how the business functions in practice, not how it is drawn on an organogram. 

What does the 45-day consultation period redundancy law require? 

Once the threshold is met, the minimum consultation period before the first dismissal takes effect is 30 days for 20 to 99 proposed redundancies, and 45 days for 100 or more. These are minimums. There is no upper limit on how long a consultation can take, and in complex restructures, running longer is often sensible. 

What the law requires in that period is genuine consultation with appropriate employee representatives, not a series of one-way briefings. The employer must provide written information covering: the reasons for the proposals, how many and which categories of employees are affected, how selection will be applied, the process and timetable, and how redundancy pay will be calculated. That information goes to the representatives, not directly to individuals, and it must be provided at the start of consultation, not partway through. 

Genuine consultation means the employer has to listen to counter-proposals and respond to them in writing. It means exploring alternatives such as voluntary redundancy, reduced hours, a temporary pay cut and redeployment to a vacancy, with an open mind rather than as a box-ticking exercise. An employer who knows on day one exactly who is going and when, but runs 45 days of meetings anyway, has not consulted in the legal sense. The Protective Award is designed for that situation. 

The 45-day consultation period redundancy timeline is not something to plan around at the end of a restructure decision. It is something to plan around at the beginning of one. The moment the board is considering 20 or more redundancies at a single site, legal advice and a clear timeline need to be in place. 

The HR1 form for redundancy: what it is, when to file it, and why it carries criminal liability 

The HR1 form for redundancy is the statutory advance notification that must be sent to the Redundancy Payments Service (part of the Insolvency Service) whenever collective consultation is triggered. It is a requirement under section 193 TULRCA, and it must be submitted at the start of collective consultation or before, and at least as many days before the first dismissal as the minimum consultation period requires. 

For 20 to 99 redundancies, that means the HR1 form redundancy notification must be submitted at least 30 days before the first dismissal takes effect. For 100 or more, at least 45 days. In practice: file it on the same day you open collective consultation. That is day one of the process, not a task to come back to once the workforce is briefed. 

The form asks for basic information: the employer's details, the establishment affected, the numbers and job types proposed for dismissal, the reason for the proposals, and when consultation started. It takes minutes to complete and is submitted online via GOV.UK. The acknowledgement that comes back is evidence of compliance. Keep it. 

What SMEs routinely overlook until it is too late is that failing to file is a criminal offence under section 194 TULRCA. The company faces an unlimited fine. Directors and officers can face personal criminal liability. This is not an employment tribunal matter with a settlement range. It is a criminal prosecution, with everything that brings. A business that gets every other part of a redundancy process right but forgets the HR1 form has still committed a criminal offence. File it first. 

The collective consultation timeline UK employers should follow 

Running collective redundancy correctly is time consuming, and it requires working in the right sequence. The redundancy consultation process flowchart for a typical SME restructure looks like this. 

Before anything else, work out whether the threshold is met. Count the proposed redundancies by establishment, not across the company. Check the 90-day window. If you are at or above 20 at a single site, collective consultation is mandatory and you need to build the process around that, not around when you wanted to announce the changes. 

On day one of consultation, two things happen simultaneously: the HR1 form goes to the Redundancy Payments Service, and the first consultation meeting takes place with employee representatives. If a recognised trade union is in place, that means union representatives. If not, a fair election for employee representatives needs to happen before consultation can start. Employees need adequate time to stand and vote. Trying to elect representatives and consult on the same day does not satisfy the obligation. 

During the minimum period, the employer meets regularly with representatives, provides responses in writing to any counter-proposals, and considers alternatives genuinely. Every meeting is noted. Every written response is kept. The paper trail from this stage is what the employer produces at tribunal if a Protective Award claim follows. Sparse notes and no written responses to counter-proposals tell a tribunal the consultation was not genuine. 

Running alongside collective consultation from the point employees are placed at risk is the individual process. This is where SMEs consistently create unfair dismissal exposure: by treating collective consultation as the only process that matters. Individual consultation is separate. Each employee at risk must receive written notification, their selection score where a matrix is used, an individual meeting with the right to be accompanied, and a right of appeal. One brief individual meeting before the redundancy letter is not enough if the collective process has been running for six weeks and the individual was never genuinely involved. 

Once the minimum period has elapsed and individual consultation is complete, redundancy notices can be issued. Statutory redundancy pay is due for employees with two years or more of continuous service. Notice must be worked or paid in lieu. These steps are not discretionary. From 1 January 2027, the two-year qualifying threshold for unfair dismissal drops to six months under the Employment Rights Act 2025, which significantly extends the number of employees who can bring a tribunal claim following a redundancy. 

Why unfair dismissal UK cases so often involve redundancy, and what that means for selection 

Redundancy is the context in which unfair dismissal UK cases arise for SMEs more than any other. That is not because redundancy is inherently unfair. It is because the process that surrounds it so often breaks down in the same places. 

Selection pool errors are the single biggest failure point. An employer who defines the pool as one team when employees in comparable roles exist elsewhere in the business has created a defensible tribunal ground before a single score has been applied. The pool should include everyone doing substantially similar work, not just the team already in the frame. Narrowing the pool to reach a predetermined result is exactly the kind of decision an employment judge will scrutinise. 

Selection criteria have to be objective and applied consistently. Skills, experience, output, and disciplinary record are all acceptable. Attendance is acceptable with significant caveats: any employee whose absences relate to pregnancy, disability, or another protected characteristic must not be disadvantaged by criteria that penalise those absences. The employer who scores on attendance without checking whether any of those absences were pregnancy-related or disability-related has created a discrimination claim on top of the unfair dismissal risk. 

Where collective consultation obligations have not been met, the tribunal's response is a Protective Award under section 189 TULRCA. This can be up to 180 days' gross pay per affected employee. It is awarded to punish non-compliance, not to compensate actual loss. That means it does not matter whether the employees concerned found other jobs quickly or whether the business was genuinely struggling financially. For a business making 20 redundancies at average UK earnings, the exposure runs comfortably into six figures. That sits alongside any individual unfair dismissal awards, not instead of them. 

Four things to get right before the first dismissal letter goes out 

Redundancy processes that end in tribunal claims are rarely the result of bad intentions. They are the result of moving too quickly, counting incorrectly, or assuming that good reasons for the redundancy make the process optional. They do not. 

Count correctly, at the right level. Check the numbers at each establishment, using the factual definition of what that establishment is, not the legal entity structure. If 20 or more redundancies are proposed at a single operational unit within a 90-day window, collective consultation is mandatory. There is no discretion here and no good-faith exception. 

File the HR1 on day one. Not after the workforce briefing, not when the process feels settled. File it on the same day collective consultation opens. File it at GOV.UK, keep the reference number, and retain the acknowledgement alongside the rest of the process documentation. This is a criminal compliance requirement, not an administrative nicety. 

Run a real consultation, not a calendar exercise. The minimum period matters, but it is the quality of the process within that period that determines whether consultation was genuine. Representatives must receive the required written information on day one. Counter-proposals must be considered and responded to in writing. Alternatives to redundancy must be explored. If the employer cannot point to a meeting note that records what the representatives said and what the employer's response was, the consultation is vulnerable. 

Run individual consultation alongside collective, not as an afterthought. Every employee at risk needs their own process: at-risk notification, selection score, individual meeting, right to be accompanied, right of appeal. This is not a courtesy. It is a legal requirement that runs in parallel to collective consultation from the point employees are placed at risk. Skipping it or compressing it into a single brief meeting creates unfair dismissal exposure that sits alongside any Protective Award claim. 

Frequently asked questions 

What triggers collective redundancy consultation in the UK? 

Proposing to dismiss 20 or more employees at one establishment as redundant within any 90-day rolling window. The obligation arises at the point of contemplating the redundancies, before decisions are made. The threshold applies per establishment, not across the business as a whole. 

How long is the collective consultation period? 

A minimum of 30 days for 20 to 99 proposed redundancies. A minimum of 45 days for 100 or more. Both are measured from the start of consultation to the date the first dismissal takes effect. These are legal minimums, not targets. In complex restructures, running longer is often appropriate and more defensible. 

What is the HR1 form for redundancy, and what happens if I don't file it? 

The HR1 form is the statutory advance notification of redundancies required under section 193 TULRCA. It is submitted to the Redundancy Payments Service at GOV.UK at the start of collective consultation or before. Failing to file is a criminal offence under section 194 TULRCA. The company faces an unlimited fine, and directors can face personal criminal liability. It is not an employment tribunal matter. It is a criminal proceeding. 

What is a Protective Award, and how much does it cost? 

A Protective Award is compensation awarded by an employment tribunal under section 189 TULRCA where an employer failed to comply with collective consultation obligations. It can be up to 180 days' gross pay per affected employee. There is no statutory cap. It is awarded to penalise non-compliance, not to compensate actual loss, so it applies regardless of whether affected employees found other jobs. For a business making 20 redundancies at average UK earnings, the exposure runs to six figures. 

Does collective redundancy also mean employees can claim unfair dismissal? 

Yes. Collective consultation and individual unfair dismissal are separate obligations. A flawed collective process makes individual dismissals significantly harder to defend, but employees also have independent unfair dismissal rights where selection was procedurally wrong, alternatives were not genuinely considered, or individual consultation was inadequate. From 1 January 2027, the qualifying period for unfair dismissal drops from two years to six months under the Employment Rights Act 2025, extending those rights to a much larger group of employees. 

A legitimate business reason for redundancy is not a defence for a broken process. 

Collective redundancy in the UK is technically demanding in a specific way: not because it is philosophically complex, but because it has hard deadlines, mandatory paperwork, and criminal sanctions that businesses only discover after they have missed them. The Employment Rights Act 2025 is tightening the window further. From January 2027, more employees will have tribunal rights, and a process that previously ended without a claim may not do so again. The Compliance Confidence Kit from The HR Doctor gives you a documented, defensible redundancy process, built before you need it. Book a free 30-minute discovery call to find out where your current process stands.