How does ACAS early conciliation work?

Notifying ACAS is the first step

Early conciliation is a legal process. You must notify ACAS before making most employment tribunal claims. Notification is done on the ACAS online notification form. ACAS then confirms your reference number and reviews the details you gave.

ACAS states you must notify within your employment tribunal time limit, and that it is your responsibility to notify in time. Check your own date on the ACAS deadline tracker.

Taking part is voluntary

ACAS offers early conciliation when you notify, and both you and your employer choose whether to take part. If you do not want conciliation, ACAS issues the certificate so you can go to an employment tribunal. If your employer declines, ACAS issues the certificate as well.

There is no obligation to settle. Any agreement is reached by you, not imposed.

What the conciliator does

ACAS assigns a conciliator who speaks with you or your representative about the dispute and the outcome you want. With your agreement, the conciliator contacts your employer to ask whether they will take part, then speaks to each side separately.

ACAS states conciliators are impartial. They can explain their role, discuss the issues with both sides, give an overview of the relevant law and explore how the dispute could be resolved. They cannot represent either side, tell you whether to agree a settlement, say how strong or weak a claim is, help you prepare a tribunal case or predict the outcome.

How long conciliation lasts

By law the early conciliation period can last up to 12 weeks. ACAS also states the service is very busy and that it can take around 9 weeks for conciliation to start.

When you notify ACAS within your time limit, the time limit is paused until early conciliation ends. A grievance, disciplinary process or appeal does not change the time limit.

The certificate and what follows

At the end of the process ACAS issues an early conciliation certificate with a number. You need that number for the ET1 claim form if you decide to make a tribunal claim. If an agreement is reached, ACAS records it in a COT3, which is legally binding.

A certificate does not make a claim. Submitting the ET1 within the applicable deadline is a separate step.

Time limits from 1 October 2026

Acas states that time limits for employment tribunal claims increased from 3 months to 6 months on 1 October 2026. The 3 month limit may still apply to problems that started before 1 October 2026. Check your deadline early and seek advice.