Acas early conciliation, step by step

What early conciliation is

Early conciliation is a process run by Acas, a government-funded body. An Acas conciliator tries to help you and your employer reach an agreement, so that you do not need to go to an employment tribunal. Acas describes it as a free service.

The conciliator is impartial. Acas says its conciliators cannot represent you, take sides, give you legal advice, tell you whether to settle or say how strong your case is. They can explain the process and the law in general terms.

Early conciliation is voluntary. You can choose not to take part, and so can your employer.

Do you have to go through Acas?

For most claims, yes. You must notify Acas before you can make an employment tribunal claim Employment Tribunals Act 1996, s.18A. Without an Acas certificate number, the ET1 claim form will usually be rejected.

There are a few exceptions. Citizens Advice gives examples: you are part of a group claim where someone has already notified Acas and named you, you are asking for interim relief, or you work for the security services. Acas says it cannot tell you whether your claim is exempt.

Acas also says that early conciliation should not be your first step. Before notifying, you would normally raise the problem with your employer, informally or with a formal grievance. Acas warns that skipping this could affect any compensation if your claim succeeds. But raising a grievance does not change the time limits. If your deadline is close, do both. The grievance letter guide explains what a grievance about final pay should contain.

Step 1: work out your last day to contact Acas

You must notify Acas within the time limit for your tribunal claim. If you contact Acas too late, the extension explained below does not apply.

Since 1 October 2026, most claims in England, Wales and Scotland have a limit of 6 months minus 1 day, if the problem happened on or after that date. For earlier problems, the old limit of 3 months minus 1 day still applies. Some Acas pages still mention only 3 months: the tribunal time limits guide explains which limit applies and which date starts the clock.

Example. A dismissal that took effect on 15 October 2026 gives a last day of 14 April 2027. That is also the last day to contact Acas. Our calculator suggests doing it by 7 April 2027, a week earlier, to leave a margin.

Statutory redundancy pay has its own rule: a written claim to your employer within 6 months of your leaving date. See what to do if your employer won’t pay your redundancy pay.

Step 2: get your details ready

Citizens Advice says the only details you must give are your name and address and your employer’s name and address. You do not have to explain the dispute at this stage.

The name matters most. Use your employer’s exact legal name, for example with “Ltd” or “plc”. It is often different from the name on the shop sign. You can find it on your payslips, your contract or the Companies House register. Citizens Advice warns that a tribunal will reject a claim if the names on the ET1 form and on the Acas certificate do not match.

If you may claim against more than one employer or person, name each of them. Have these ready too:

• your dates of employment and your job title;
• the sums you think are owed, with how you worked them out;
• the name of any representative, such as a trade union representative;
• any support you need, such as an interpreter or contact by email only.

Step 3: notify Acas, online or by phone

There are two ways to notify Acas:

• Online, with the form on the “Notify Acas” page of the Acas website. If you create a memorable word, you can save the form and come back to it. Once you submit it, you cannot change it, so check your answers first.
• By phone, on 0300 123 1122, Monday to Friday, 9am to 5pm. If you cannot hear or speak on the phone, use Relay UK on 18001 0300 123 1122. You can ask for an interpreter, and the service is available in Welsh.

The Acas page does not mention a paper form. If you cannot use the online form, it says to contact its early conciliation team.

Keep the acknowledgement email. Citizens Advice suggests it as proof of the day you contacted Acas. That day is called Day A.

Step 4: what happens next

Acas describes these steps:

1. Acas asks whether you want to try early conciliation. If you do not, it issues a certificate straight away.
2. If you do, Acas sends a confirmation with your reference number and may call you to check your details.
3. Your case goes to a conciliator. On its “Notify Acas” page, Acas says it can take around 9 weeks for conciliation to start.
4. The conciliator talks to you about the dispute and the outcome you want.
5. With your agreement, the conciliator contacts your employer to see whether it is willing to talk.
6. If it is, the conciliator speaks to each side separately and passes on offers.

Early conciliation can last up to 12 weeks. This maximum has applied to notifications made since 1 December 2025; before that, it was 6 weeks.

Step 5: the outcome, a COT3 or a certificate

There are two possible endings.

Outcome	What it means
Agreement	Acas writes it up as a COT3, a legally binding agreement. Acas says you must keep to it once both sides have agreed, even before signing. The case is closed and there is no tribunal hearing.
No agreement, or your employer will not talk	Acas sends a certificate with a number. You need that number for box 2.3 of the ET1 form if you still want to claim.

When you receive the certificate, note the date: that is Day B. Citizens Advice suggests asking for it by email, so you can prove when it arrived. Check the names, the addresses and the date you first contacted Acas. If something is wrong, contact your conciliator.

An agreement can also be made outside Acas, as a settlement agreement, with its own legal conditions: see how settlement agreements work.

How early conciliation changes your deadline

If you contact Acas in time, the law moves your deadline ERA 1996, s.207B:

• the days from the day after Day A up to and including Day B do not count;
• if your deadline would then fall before one month after Day B, it moves to one month after Day B.

Acas puts it simply: you will have at least 1 month from the date you received the certificate.

Example, continued. Dismissal effective 15 October 2026, last day 14 April 2027. You contact Acas on 10 January 2027 and receive the certificate on 20 February 2027. The 41 days from 11 January to 20 February are added: the new last day is 25 May 2027. That is later than one month after Day B (20 March 2027), so it stays at 25 May. Our calculator suggests making the ET1 claim online by 18 May 2027.

Two warnings. Citizens Advice says that if your employer starts early conciliation, your deadline is not extended. And if you contact Acas after your time limit has passed, there is no extension at all. Only an employment tribunal can decide whether a claim is in time. The tribunal time limits guide gives more dated examples, including the one-month rule.

Mistakes to avoid

• Waiting for the outcome of a grievance or an appeal before contacting Acas.
• Using the trading name instead of the legal name.
• Counting your deadline from the date conciliation started, rather than from the date in the law.
• Losing the dates of Day A and Day B.

Northern Ireland

Northern Ireland does not use Acas. Conciliation there is with the Labour Relations Agency, under different rules and time limits. This guide covers England, Wales and Scotland only.

Next steps

1. Check your dates, free. The time limit calculator gives your last day to contact Acas with a suggested earlier date, and your new ET1 deadline once you enter Day A and Day B. You can ask for a free email reminder before each date.
2. Prepare, free. The Acas preparation sheet is pre-filled with the details you have entered. You then notify Acas yourself.
3. Next step. If you receive a certificate, the free ET1 preparation sheet maps your details to the boxes of the form. You fill in and submit the form yourself. Acas, Citizens Advice, a trade union or a solicitor can also help you.