ACAS Early Conciliation Guide

What is ACAS early conciliation?

ACAS (Advisory, Conciliation and Arbitration Service) is an independent public body that helps resolve workplace disputes. Before an employee can submit a claim to the employment tribunal, they must first notify ACAS and go through a process called early conciliation. This became mandatory in May 2014.

The purpose is to give both sides an opportunity to settle the dispute without the cost and stress of tribunal proceedings. It is free, voluntary in spirit (you cannot be forced to settle), and confidential.

How does it work?

1. You notify ACAS — By phone (0300 123 1100) or online at acas.org.uk. You provide basic details: your name, employer's name, and the type of dispute.
2. ACAS contacts you — A conciliator calls you to understand your situation and explain the process.
3. ACAS contacts your employer — The conciliator approaches your employer to see if they are willing to discuss settlement.
4. Shuttle conciliation — The conciliator acts as a go-between, relaying offers and responses between the parties. They do not take sides or give legal advice, but can help both parties understand a realistic range of outcomes.
5. Either a settlement is reached, or not — If settlement is agreed, it is recorded in a COT3 agreement (see below). If not, ACAS issues an Early Conciliation Certificate allowing you to proceed to tribunal.

How long does early conciliation take?

The early conciliation period lasts up to 6 weeks (with a possible extension of up to 2 more weeks by mutual agreement). During this period, the tribunal time limit is paused. Once the certificate is issued (either because conciliation ended or 6 weeks elapsed), the clock restarts — and you typically have one calendar month from the certificate date to submit your ET1.

Does ACAS conciliation stop the tribunal clock?

Yes — this is crucial. When you notify ACAS, Day A (the start of conciliation) is recorded. If you receive your certificate on Day B, the tribunal time limit is extended by the number of days between Day A and Day B, plus an additional month. This means that even if you notify ACAS on the last day of the 3-month period, you will have additional time after conciliation ends.

Do I have to engage with early conciliation?

You must notify ACAS — but you are not required to actively engage in negotiations. If you or your employer do not wish to conciliate, ACAS will issue the certificate promptly, and you can proceed to tribunal. However, refusing to engage can sometimes be taken into account by a tribunal when considering costs.

What is a COT3 agreement?

If early conciliation results in a settlement, the terms are recorded in a COT3 agreement. A COT3 is legally binding and settles the claims covered by it — similar to a settlement agreement, but simpler. Unlike a settlement agreement, you do not need independent legal advice for a COT3 to be valid (though taking advice is strongly recommended). Once signed, you cannot pursue the covered claims at tribunal.

COT3 agreements are commonly used for straightforward disputes. For more complex cases involving multiple claims, multiple payments, or where confidentiality is important, a full settlement agreement (with solicitor involvement) is usually preferable.

ACAS during live tribunal proceedings

Even after tribunal proceedings have been issued, ACAS conciliators (known as "open period" conciliators) remain available to assist with settlement. Many cases settle at this stage — often just before the final hearing, when both parties have seen each other's witness statements and can assess the risks more clearly.

The ACAS early conciliation process step by step

Understanding exactly what happens during early conciliation — and in what order — helps you prepare properly and avoid being caught off guard. The process is structured but informal, and knowing the stages will help you engage with confidence.

1. Step 1 — Notification (Day A): You contact ACAS online or by phone (0300 123 1100) and provide your name, employer details, and the nature of the dispute. This is the moment Day A is recorded and your tribunal clock is paused.
2. Step 2 — ACAS calls you: Within a few working days, an ACAS conciliator telephones you to explain the process and understand your situation. They are neutral — they will not advise you on the strength of your claim, but they will listen carefully.
3. Step 3 — Employer contact: ACAS contacts your employer to inform them of your notification and ask whether they wish to participate. Employers are not legally required to engage, but most do — a tribunal claim is expensive and reputationally risky.
4. Step 4 — Shuttle conciliation: The conciliator acts as a go-between, carrying offers and responses between the parties. You will never be in the same room as your employer. The conciliator may help reality-check unrealistic positions on either side.
5. Step 5 — Settlement or certificate: If a deal is reached, it is recorded in a COT3. If not — either because one party refuses to engage, or because six weeks pass without agreement — ACAS issues an Early Conciliation Certificate (EC Certificate).

The EC Certificate is a document stating the dates of Day A and Day B (the day the certificate was issued). You will need this certificate number to complete your ET1 tribunal claim form — without it, your claim cannot be accepted.

What can ACAS help you negotiate?

Many employees assume that ACAS conciliation is only about a financial payment. In reality, the range of outcomes that can be agreed through a COT3 is much broader. Because the COT3 is a contract between the parties, almost any term that both sides agree to can be included. Common negotiating points include:

• Compensation payments — a lump sum to settle financial losses (lost earnings, notice pay, redundancy pay)
• Notice pay — agreement to pay out your contractual notice period if not already paid
• Holiday pay — settlement of any outstanding accrued but untaken holiday
• Agreed reference — a specific reference wording or a neutral factual reference (dates of employment, job title) to prevent a damaging or inconsistent reference
• Departure reason — how your leaving is described internally and to future employers (e.g., "resigned by mutual agreement" rather than "dismissed")
• Withdrawal of disciplinary sanctions — removal of a final written warning or other sanction from your record
• Confidentiality — if you want to keep the settlement terms private (or your employer does), this can be agreed
• Non-disparagement — agreement that neither party will make derogatory statements about the other
• Return of property — agreed timeline for returning equipment or personal belongings
• Outstanding expenses and benefits — settlement of any unpaid expense claims or accrued benefits

If ACAS conciliation fails

When conciliation does not result in a settlement, ACAS issues your Early Conciliation Certificate and your options become clearer. You are not left empty-handed — you now have the evidence of your Day A and Day B dates and can proceed to tribunal if you choose.

COT3 vs tribunal: which route to take?

Even after receiving the EC Certificate, settlement remains possible at any point before the tribunal issues its judgment. Many claims settle after ET1 is filed, after the response (ET3) is submitted, or even in the days immediately before a final hearing. The tribunal process itself creates pressure on both sides to resolve matters.

Key points to understand once conciliation has formally ended:

• Time limits reset: Once Day B is recorded on your EC Certificate, your tribunal deadline is calculated as the later of: (a) one calendar month from Day B, or (b) the original unexpired portion of your three-month time limit plus any extension. In practice, you typically have at least one month from the certificate date to submit your ET1.
• The COT3 route remains open: Even without active ACAS involvement, you and your employer can still reach a settlement and record it in a COT3 at any time before judgment. ACAS conciliators remain available throughout live proceedings.
• Settlement agreement route: After conciliation fails, an employer may approach you (or you may approach them) with a full settlement agreement — particularly once you have filed your ET1 and the seriousness of the claim is apparent.
• Costs risk: If a tribunal finds that a party acted unreasonably in refusing to engage with settlement (including during ACAS conciliation), it can make a costs order against that party. This is rare but real — and it encourages genuine engagement rather than tactical stonewalling.