ACAS Just Called. One of Your Employees wants to Make a Claim. Now What?
The Thrive. employer’s guide to Early Conciliation, and how to stop the risk before it becomes a tribunal claim
You’ve had the message.
From ACAS.
Out of the blue.
And suddenly, a name you weren’t expecting shows up linked to the words “employment dispute.”
This is the start of the Early Conciliation (EC) process, and whether it’s a misunderstanding, a missed grievance, or something bigger brewing, it’s now formal.
And the decisions you make in the next few weeks will determine whether this ends in clarity — or a costly tribunal.
What Is Early Conciliation (EC), Really?
EC is a mandatory step in the UK employment tribunal process. An employee can’t lodge an ET1 claim unless they’ve first contacted ACAS and been offered conciliation.
ACAS will then reach out to you (the employer) to see whether you’re willing to talk.
But here’s the truth:
Most employers either freeze, fumble, or go in swinging. And all three cost you.
Handled well, EC is a golden window to:
De-escalate the situation
Understand what’s gone wrong
Resolve it privately before reputations or finances are on the line
When Can an Employee Start EC?
The legal deadlines to start Early Conciliation are tight, but nuanced.
Standard time limit:
3 months minus 1 day from the date of dismissal, incident, or last alleged act
Extended time limit (6 months minus 1 day) for:
Statutory redundancy pay claims
Equal pay claims
Unfair dismissal claims relating to industrial action
Certain union-related or Armed Forces claims
Once the employee contacts ACAS:
The tribunal time limit pauses during conciliation
It resumes after a certificate is issued
They then have at least 1 more month to file an ET1 claim
How Long Does Early Conciliation Last?
Initial window: 1 calendar month
Extension: +14 days, if both parties agree
Max duration: 6 weeks
If you ignore it or refuse to participate, ACAS will issue a certificate, and the employee is legally clear to proceed to tribunal.
Where Employers Go Wrong…and What It Costs Them
Let’s look at two real cases and why they matter:
Case 1: Mills v Virgin Active¹
The employee claimed unfair dismissal and age discrimination. Virgin Active failed to properly investigate and made assumptions about her health.
But the problem wasn’t just the dismissal — it was how they responded to ACAS.
They didn’t engage meaningfully.
They came across as dismissive and disinterested.
The tribunal saw this as evidence of poor culture and bad faith — awarding £95,000, including aggravated damages.
Why this matters: Tribunals assess behaviour before the hearing. If you look hostile, indifferent, or unprepared during EC, it shapes their view of your credibility.
Case 2: Gallacher v Abellio ScotRail²
An employee was dismissed without a formal hearing, which usually spells disaster.
But the employer had:
Clear, contemporaneous records
A strong justification based on breakdown of trust
Consistent internal handling
The tribunal accepted the employer’s argument and dismissed the claim.
Why this matters: If you’ve got solid documentation and act early — even imperfect processes can be defended. But you need to show thought, fairness, and proper intention — especially during EC.
My Real-World Example: Covid-19, 1000+ Workers, and a Misunderstood Pay Dispute
During the pandemic, I led a large-scale NHS immunisation project that mobilised over 1000 people. One of the workers later went straight to ACAS, claiming she hadn’t received the right holiday pay.
She didn’t raise it with her line manager.
She didn’t use our grievance process.
She just got frustrated — and jumped to conciliation.
Now, I could’ve gone in defensive. Told ACAS we were in the right. Dismissed the concern.
Instead, I used the window.
We paused.
Investigated.
Found that the team hadn’t explained the variable holiday pay model clearly enough.
We addressed it, clarified her entitlement, and issued a top-up.
That was the end of it.
Why this matters: If I’d let ego or red tape take over, we could’ve had a holiday pay, breach of contract, and even discrimination claim on our hands — all over a communication error.
Common Triggers That Lead to EC (and ET1s)
Want to avoid getting here in the first place? Here are the most common triggers I see that lead to EC:
Poor documentation of performance concerns or disciplinary warnings
Inconsistent treatment (especially when others weren’t held to the same standard)
Unclear contracts, outdated policies, or vague job roles
Poorly handled grievances — or worse, none at all
Off-the-record conversations replacing formal processes
Timeline: What Happens (And When)
Stage: Incident or Dismissal
Timeline: Day 0
The clock starts ticking from the date of dismissal or the incident giving rise to the potential claim. This is when the employee’s time limit to act begins.
Stage: Employee contacts ACAS
Timeline: Within 3 or 6 months
The employee must contact ACAS to start Early Conciliation within 3 months of the incident for most claims (e.g., unfair dismissal), or 6 months for specific cases like equal pay or redundancy pay. Missing this deadline can mean losing the right to bring a claim.
Stage: Early Conciliation begins
Timeline: ACAS contacts employer
ACAS assigns a conciliator who reaches out to the employer. The aim is to see if a settlement can be reached without going to tribunal, saving time, cost, and stress for everyone involved.
Stage: Conciliation window
Timeline: 1 month (+14 days optional)
ACAS has 1 calendar month to facilitate discussions. This period can be extended once by up to 14 days if both sides agree there’s a chance of resolution. During this window, claim time limits are paused.
Stage: Certificate issued
Timeline: If no agreement is reached
If conciliation fails or either side decides to end it, ACAS issues an Early Conciliation Certificate. The certificate is essential: a tribunal claim cannot proceed without it.
Stage: ET1 claim submitted
Timeline: Within 1 month post-certificate
Once the certificate is issued, the claimant has a strict deadline of 1 month to lodge an ET1 claim form with the Employment Tribunal. Timing is critical — missing this window can prevent the claim entirely.
If You’re Already in the Thick of It
You’ve got the call. The name shocked you. The claim caught you off guard. Here’s what to do:
1. Don’t ignore it.
Even if you think it’s nonsense, silence looks arrogant. Engage, even if just to request more info.
2. Investigate — now.
Pull records. Talk to managers. If you’re missing a grievance response or disciplinary file, admit it. Fix it.
3. Don’t wing it.
This isn’t the time for vague reassurances or HR theory. Get help — someone who’ll tell you what matters and what doesn’t.
Final Word from Rosie
If you’re running a business, I know you’re not looking for HR theory.
When ACAS gets in touch, it’s not just admin - it’s a signal that something needs handling, fast.
This isn’t the time to wonder whether your HR advisor is going to quote a policy or give you a lecture.
It’s time to protect what you’ve built, get to the root of the issue, and lead your team through it, without making it worse.
That’s what I do. I’ve been in the thick of it, and I’ll help you steady the ground and make the right next move.
Got the call? I’ve got you. Book a clarity call at www.thrive-hr.uk.
References
¹ Mills v Virgin Active Ltd [2019] ET/2201493/2018
² Gallacher v Abellio Scotrail Ltd [2020] UKEATS/0027/19/SS
³ Ministry of Justice Tribunal Statistics Q2 2024: gov.uk
⁴ ACAS Code of Practice on Disciplinary and Grievance Procedures (2024)
⁵ The Employment Rights (Increase of Limits) Order 2025
