Answers · UK 2025/26

What is ACAS early conciliation and is it compulsory before an employment tribunal claim?

ACAS early conciliation is a compulsory first step before most employment tribunal claims in England, Scotland and Wales, requiring a prospective claimant to notify ACAS and allow a period (up to six weeks) for a conciliator to try to help the parties settle before a tribunal claim can normally be lodged.

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Early conciliation, run by the Advisory, Conciliation and Arbitration Service (ACAS), sits between a workplace dispute and a formal employment tribunal claim, and for most types of claim it is a mandatory step, not an optional one. **Why it exists** The aim of early conciliation is to resolve as many workplace disputes as possible without the cost, delay and stress of a full tribunal hearing, by giving a neutral ACAS conciliator a fixed window to help the employer and employee reach a voluntary settlement. **How the process works** Before lodging most types of tribunal claim, a prospective claimant must first notify ACAS, usually by completing an early conciliation notification form online. ACAS then makes contact with both parties and offers a period (up to six weeks, which can sometimes be extended by mutual agreement) during which a conciliator tries to help negotiate a resolution -- this might involve compensation, an agreed reference, or other terms, often recorded in a formal settlement (COT3) agreement if successful. **What happens if conciliation does not resolve things** If no settlement is reached, ACAS issues an early conciliation certificate, and the prospective claimant then generally has a limited window (extended to account for time spent in conciliation) to lodge their actual claim with the employment tribunal -- the certificate number must be included on the tribunal claim form (unless a specific exemption applies). **Worked example** An employee believes they were unfairly dismissed on 1 March. Because the ordinary tribunal time limit for unfair dismissal is three months less one day from the effective date of termination, they would normally need to lodge a claim by around 28 May. If they notify ACAS on 1 April and the conciliation period runs until 1 May without settlement, the time spent in conciliation is added back on to the claim deadline, giving extra time beyond the original three-month limit to actually lodge the tribunal claim -- missing the underlying tribunal deadline (even accounting for this extension) can mean losing the right to claim altogether. **Claims where early conciliation does not apply** A small number of claim types are exempt from the compulsory early conciliation requirement, and multiple claimants bringing connected claims sometimes have specific rules about how the requirement applies to each of them -- but the large majority of individual employment claims, including unfair dismissal, discrimination, unlawful deductions from wages, and redundancy pay disputes, do require early conciliation first. **Settlement during conciliation is legally binding** If a settlement is reached during early conciliation and recorded on a COT3 form (a form specific to ACAS-brokered settlements), it is legally binding and normally prevents the employee bringing a tribunal claim about the same matter afterwards, similar in effect to a formal settlement agreement negotiated with legal advice. **Practical tip** If you believe you have an employment claim, contact ACAS to start early conciliation well before your tribunal time limit is close to expiring, keep a clear record of the certificate number issued, and treat the conciliation period as a genuine opportunity to resolve the dispute without the cost and uncertainty of a full tribunal hearing.