ACAS Early Conciliation: How Long It Takes & What Happens

This article applies to England, Wales and Scotland.

Important: This guide provides general information about UK employment law. It is not legal advice. Every situation is different. If you need advice specific to your circumstances, consider speaking to a solicitor or contacting ACAS.

In brief: ACAS early conciliation is a free, confidential service that tries to help you and your employer resolve a workplace dispute without going to tribunal. It is also a legal requirement — you cannot start a tribunal claim without an ACAS early conciliation certificate. Since 1 December 2025, the process can last up to 12 weeks, and during that time your tribunal deadline is paused.

Last updated: March 2026

What Is ACAS Early Conciliation?

ACAS early conciliation is a process where an independent conciliator from ACAS acts as a go-between to help you and your employer reach an agreement. It sits between raising a complaint informally (or through a grievance) and submitting a formal claim to the employment tribunal.

Since 2014, it has been mandatory. Before you can file an ET1 form to start a tribunal claim, you must first notify ACAS of your dispute. ACAS then contacts your employer and tries to help reach a resolution. If it works, your dispute is settled without a hearing. If it does not, ACAS gives you a certificate that allows you to proceed to tribunal.

The service is completely free. You do not need a solicitor to use it.

Why It Matters

Early conciliation matters for three reasons:

It is a legal gateway. Without an ACAS early conciliation certificate number, the tribunal will reject your ET1 form. There are very limited exemptions — for example, certain claims against the same respondent where conciliation has already been attempted — but for most people there are no exceptions.

It pauses your time limit. The clock stops on your tribunal deadline while conciliation is active. If you start conciliation with two weeks left on your deadline, you do not lose those two weeks — they are preserved until the certificate is issued, at which point you get at least one calendar month to file your ET1.

It can resolve things faster and better than a tribunal. A negotiated settlement can include things a tribunal cannot order — like an agreed reference, a quicker payout, or confidentiality. Tribunal claims currently take an average of around 40 weeks from receipt to hearing. Conciliation can be done in weeks.

How the Process Works

Step 1: Notify ACAS

You start by contacting ACAS. You can do this:

Online at www.acas.org.uk/early-conciliation (the quickest way)
By phone on 0300 123 1100

You provide your details, your employer's details, and a brief description of the dispute. You do not need to set out a full legal case — just enough for ACAS to understand the nature of the complaint.

Do this before your tribunal time limit expires. If the deadline passes without you having contacted ACAS, you may lose the ability to bring a claim.

Step 2: ACAS Contacts Your Employer

After receiving your notification, ACAS contacts your employer and offers to conciliate. Your employer is under no obligation to participate — they can refuse. But most employers do engage, at least initially, because ignoring ACAS does not look good if the case goes to tribunal later.

Step 3: The Conciliation Period

From 1 December 2025, the maximum conciliation period is up to 12 weeks, under the Employment Tribunals (Early Conciliation: Exemptions and Rules of Procedure) (Amendment) Regulations 2025. This doubled from the previous maximum of six weeks. The change applies to all notifications made on or after 1 December 2025 — cases started before that date continue under the old six-week rule.

The extension was introduced because demand for early conciliation has been rising sharply. ACAS handled over 117,000 early conciliation cases in 2024/25, with approximately 45,000 live cases at March 2025. The previous six-week window was too short for conciliators to be allocated in many cases — it was often taking up to four weeks just to make first contact, leaving under two weeks for actual negotiation. The 12-week period will be reviewed in October 2026 to assess whether it should remain or revert.

During the conciliation period, the ACAS conciliator will:

Speak to you and your employer separately (they do not arrange three-way meetings at this stage)
Explore whether there is common ground
Relay offers and counteroffers between you
Help both sides understand the strengths and weaknesses of their positions

The conciliator is neutral. They do not take sides, do not give legal advice, and do not tell you what to do. Their role is to help both sides reach an agreement.

Everything you say to ACAS during conciliation is confidential and without prejudice — meaning it cannot be used as evidence at a tribunal if conciliation fails.

Step 4: Outcome

One of three things happens:

Settlement (COT3) — if you and your employer reach an agreement, it is recorded on a form called a COT3. This is a legally binding settlement. Once signed, you cannot bring a tribunal claim for the issues covered by the COT3. It is enforceable through the county court if your employer does not honour it.

No settlement — if conciliation does not work, or your employer refuses to participate, ACAS issues an early conciliation certificate with a unique reference number beginning with either A or B. An A-number means ACAS attempted conciliation. A B-number means the process ended without contact (for example, because you requested a certificate immediately without attempting settlement). You use this reference number to submit your ET1 form to the tribunal.

You decide not to proceed — you can withdraw at any time. ACAS will still issue a certificate so you have the option to go to tribunal later if you change your mind.

Time Limits and How Conciliation Affects Them

The detail here matters.

Most tribunal claims must be filed within three months minus one day from the event you are complaining about. Starting early conciliation pauses this clock.

How the maths works:

Day A — the day you (or ACAS on your behalf) send the early conciliation notification to ACAS
Day B — the day you receive the early conciliation certificate

The period between Day A and Day B does not count towards your time limit. On top of that, when the clock restarts, you get at least one calendar month from Day B to file your ET1 — even if your original deadline would have been sooner.

What to do next

Know your position before you pick up the phone.

Assess your case first

Example: Your dismissal date is 1 March 2026. Your normal deadline would be 29 May 2026. You contact ACAS on 20 May. ACAS issues the certificate on 10 June. You then have until at least 10 July to file your ET1 — because you get one month from the certificate date.

What this means in practice with the 12-week period

If you notify ACAS early in your three-month window and conciliation runs for the full 12 weeks, your effective deadline to file at tribunal could be around seven months from the original event. Once the ERA 2025 time limit extension takes effect in October 2026 — extending most claims from three months to six months — this combined window could reach approximately nine to ten months.

Extension of time: when the deadline is missed

Tribunals can extend the time limit where it was not reasonably practicable to bring a claim in time. This is a strict test. In Luton Borough Council v Haque [2021], the EAT confirmed that ignorance of the time limit alone is not sufficient — the claimant must show they could not reasonably have known about the deadline. Relying on an extension is not a safe strategy. If you are near your deadline, notify ACAS immediately.

If you think you may be close to or past your deadline, see our guide: Workplace Deadlines and Time Limits.

What Makes Conciliation Succeed or Fail

ACAS handled over 117,000 early conciliation cases in 2024/25. A significant proportion of claims that enter early conciliation settle without reaching a tribunal hearing — for unfair dismissal, around 27% settle at the ACAS stage based on recent MoJ tribunal data.

Factors that help:

Both parties engaging in good faith
A clear sense of what you would accept (have a realistic figure in mind before conciliation starts)
Willingness to compromise — conciliation is about finding middle ground
Strong evidence (your employer is more likely to settle if they know the case against them is solid)

Factors that hinder:

Your employer refusing to engage (more common with small businesses)
Unrealistic expectations on either side
Emotional rather than practical focus
Delay — the longer conciliation drags, the less likely a deal

A practical tip: before conciliation starts, work out your best alternative to a negotiated agreement. That means: if conciliation fails, what is your realistic tribunal outcome? Factor in the time, stress, and uncertainty of a tribunal claim. If your employer offers something close to what you would realistically receive at tribunal, that is worth considering seriously.

What Can You Settle For?

There is no formula. Settlement amounts depend entirely on the circumstances of your case. Typical elements of a conciliation settlement include:

Financial compensation — a lump sum payment
An agreed reference — particularly valuable if you were dismissed and concerned about what your employer might say to future employers
An apology or acknowledgment — sometimes important on a personal level
Agreed terms of departure — including how the termination is described
Confidentiality — a mutual agreement not to discuss the terms or the dispute

The financial element is usually negotiated as a multiple of your likely losses at tribunal, discounted for the risk of losing and the time value of receiving money now rather than in 12 months.

The COT3 Agreement

A COT3 is the formal record of an ACAS-brokered settlement. Key points:

It is legally binding on both parties the moment it is signed
Unlike a settlement agreement, you do not legally need independent legal advice to sign a COT3 — though getting advice before signing is strongly recommended
It can cover some or all of the claims you raised
It is enforceable through the county court without starting a new tribunal claim
It is usually confidential between the parties

Once you sign a COT3, you cannot bring a tribunal claim for the issues it covers. The finality is the point — ACAS conciliation is a full resolution, not a pause.

ACAS Conciliation vs Settlement Agreements

These are two distinct mechanisms and are often confused:

	ACAS Conciliation (COT3)	Settlement Agreement
Who facilitates	ACAS conciliator	Usually negotiated between solicitors
Legal advice required	No (but recommended)	Yes — mandatory requirement
Cost	Free	Employer usually pays legal fees (typically £250–£500 + VAT)
When used	Before or alongside a tribunal claim	Any time, but often when employment is ending
Legally binding	Yes	Yes
Confidential	Yes	Yes (usually with a specific confidentiality clause)

A COT3 reached through ACAS is just as binding as a settlement agreement. The practical difference is that settlement agreements involve more detailed drafting, cover a wider range of claims, and require you to have received independent legal advice — which is a statutory requirement under s.203 ERA 1996.

Do You Need a Solicitor?

Not for the ACAS conciliation process itself. Many people go through conciliation without legal representation.

However, getting legal advice before agreeing to a settlement is strongly recommended. Once you sign a COT3, it is final. A solicitor can help you assess whether the offer is fair relative to the strength of your case and your likely tribunal outcome.

Some solicitors offer a fixed fee for advising on settlement terms. No-win-no-fee arrangements are available for some claim types.

For options on free and low-cost legal help, see: Where to Get Help With Work Problems.

Frequently Asked Questions

Is my employer told I have contacted ACAS?

Yes. ACAS contacts your employer after you notify them. What you have told ACAS in confidence is not shared with your employer — only the fact that you have started conciliation and the general nature of the dispute.

What if my employer ignores ACAS?

ACAS cannot force your employer to participate. If they do not respond or refuse to engage, ACAS will issue your certificate and you can proceed to tribunal. Your employer's refusal to conciliate can also work in your favour at tribunal.

What does the A or B on my certificate reference mean?

An A-number (e.g. A123456/25) means ACAS attempted conciliation. A B-number means the process ended without ACAS contacting your employer — for example, because you requested a certificate immediately. Both are valid for submitting an ET1.

Can I contact ACAS about multiple claims?

Yes. You can notify ACAS about all the claims you intend to bring. You will receive one certificate that covers them all, provided they relate to the same employer.

Does conciliation cost anything?

No. The ACAS early conciliation service is completely free.

How long does the process take?

Up to 12 weeks maximum (for cases notified from 1 December 2025). In practice, many cases resolve much faster — or ACAS issues a certificate quickly if your employer declines to engage.

What if I settle through ACAS and my employer does not pay?

A COT3 is a legally binding agreement. If your employer does not honour it, you can enforce it through the county court. You do not need to start a new tribunal claim.

Can I still go to tribunal after conciliation?

Yes, unless you signed a COT3 settlement. If conciliation did not result in a settlement, your certificate allows you to file your ET1 and proceed to tribunal.

Has the ACAS early conciliation period always been 12 weeks?

No. The maximum was six weeks until 1 December 2025, when it doubled to 12 weeks under the Employment Tribunals (Early Conciliation: Exemptions and Rules of Procedure) (Amendment) Regulations 2025. Cases notified before 1 December 2025 continue under the old six-week limit. The 12-week period is subject to government review in October 2026.

Sources

"Early Conciliation", ACAS (2025) — ACAS: Early Conciliation
Employment Tribunals (Early Conciliation: Exemptions and Rules of Procedure) (Amendment) Regulations 2025 — Early Conciliation (Amendment) Regulations 2025
Employment Rights Act 1996 — Employment Rights Act 1996
Enterprise and Regulatory Reform Act 2013, Section 7 — Enterprise and Regulatory Reform Act 2013, s.7
Employment Rights Act 2025 — Employment Rights Bill 2025
"Employment Tribunal Statistics", Ministry of Justice (Q2 2025/26) — GOV.UK Tribunals Statistics
Luton Borough Council v Haque [2021] IRLR 542 (EAT) — extension of time test
"Making a Claim to an Employment Tribunal", GOV.UK — GOV.UK: Make a Tribunal Claim

Related Guides

acasearly conciliationsettlementtribunal claimscot3time limitsemployment tribunalconciliation periodERA 2025

ACAS Early Conciliation: What It Is, How It Works, and What to Expect