This guide is maintained as a current resource for July 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
Detailed guide explaining whether ACAS early conciliation is mandatory before an employment tribunal claim in England and Wales, including statutory requirements, exceptions, time limit effects and practical steps for claimants and employers.
Before most employment tribunal claims in England and Wales can be submitted, a prospective claimant must go through ACAS Early Conciliation. This requirement shapes the way many workplace disputes are first addressed and has important implications for time limits and case strategy. This article explains when early conciliation is mandatory, when it is not, how the requirement works in practice, and what happens if the process is declined or unnecessary. All explanations are grounded in current official sources.
Introduction
ACAS Early Conciliation was introduced to help resolve workplace disputes at an early stage and reduce the number of cases that proceed to an employment tribunal. It is a statutory process provided by the Advisory, Conciliation and Arbitration Service (ACAS) that gives claimants and respondents an opportunity to settle a dispute without formal litigation. The requirement to notify ACAS and offer early conciliation arises from legislation and tribunal procedural rules and applies in most, but not all, situations.
What Early Conciliation Is
Early conciliation is a free, confidential process where an ACAS conciliator speaks separately with the claimant and the respondent (usually the employer) to explore whether the dispute can be resolved without an employment tribunal claim. The conciliator does not give legal advice, decide the outcome, or represent either party. Instead, the role is to facilitate discussions that could lead to settlement or narrow the issues in dispute.
Participation in settlement discussions during early conciliation is voluntary for both parties, but the notification of ACAS must be made before most claims are filed. ACAS then issues an early conciliation certificate which is required to submit a tribunal claim on form ET1.
When ACAS Early Conciliation Is Mandatory
Under current practice:
- A prospective claimant must notify ACAS of their intention to make most types of employment tribunal claims before submitting a claim to the tribunal. This requirement effectively makes early conciliation a mandatory procedural step for many claims, including those for unfair dismissal, discrimination, unpaid wages, breach of contract, redundancy rights, and other statutory workplace rights.
- The notification triggers the early conciliation process and pauses the statutory time limit for filing a tribunal claim. The time limit “clock” stops from the day ACAS receives the notification until a certificate is issued, after which the claimant generally has at least one month to lodge the ET1.
Because of this statutory framework, early conciliation is mandatory in most cases where a tribunal claim is contemplated, and failing to notify ACAS in time means the tribunal may not accept the claim.
Situations Where Early Conciliation Is Not Required
There are specific exceptions where a claimant does not need to notify ACAS before making a tribunal claim:
- Already‑conciliated claims: If another person (claimant) has already been through early conciliation against the same respondent about the same dispute, a claimant may not have to repeat the ACAS notification, provided they can evidence that the conciliator dealt with the dispute jointly.
- Interim relief in unfair dismissal: A claimant seeking interim relief (an urgent order to reinstate or preserve employment) as part of an unfair dismissal claim does not have to complete early conciliation before making that part of the application. However, early conciliation must still be completed for any other tribunal claims unless exempt.
- Respondent‑initiated conciliation: If a respondent has already notified ACAS and begun early conciliation regarding the dispute, a claimant may not need a separate notification, again subject to evidential requirements.
- Claims ACAS cannot conciliate: Certain types of claims or issues fall outside ACAS's statutory power to conciliate. Where ACAS does not have jurisdiction to conciliate the specific claim, the requirement does not apply. In such cases, early conciliation will not be offered because ACAS cannot conciliate the matter.
These exceptions are relatively narrow and depend on the nature of the claim and the procedural context. Anyone unsure whether an exemption applies should consider confirming with ACAS or seeking legal advice.
Participation: Offers vs Engagement
Although notification to ACAS is compulsory for most claims, actual engagement in the conciliation talks is voluntary for both the claimant and the respondent. Neither side can be forced to negotiate or take part in settlement discussions offered by ACAS. If a party declines to engage, ACAS will issue the early conciliation certificate so a tribunal claim can proceed.
This means that while the procedural step of notifying ACAS is mandatory, participation in more substantive discussions beyond notification is a matter of choice. Employers often choose not to participate because they prefer to defend the claim in a tribunal or believe the claim lacks merit. Refusal to participate does not prejudice the position in subsequent tribunal proceedings.
Time Limit Implications
One of the principal reasons early conciliation is mandatory is its effect on statutory time limits. Employment tribunal claims generally must be lodged within three months minus one day from the date of the act complained of (such as dismissal), or six months minus one day for specific claims like statutory redundancy pay. Notifying ACAS within these periods means the countdown is paused during early conciliation. Once the early conciliation certificate is issued, claimants have additional time (usually at least one month) to submit the ET1 form.
Failing to notify ACAS within the applicable time limit usually results in the tribunal rejecting the claim as out of time, unless the claimant establishes grounds for an extension (e.g., it was not reasonably practicable to take earlier action).
Practical Considerations
- Start early: Prospective claimants should notify ACAS as soon as they know they may make a claim to preserve time limits.
- Understand exceptions: In some limited situations, early conciliation may not be required; confirming this with ACAS or a legal adviser can prevent unnecessary steps.
- Certificates are essential: An ACAS early conciliation certificate number is required to include on the ET1 tribunal claim form, even if negotiations do not take place.
- Participation is voluntary: Neither party can be forced into settlement talks, though engaging meaningfully with ACAS can result in cost and time savings and may avoid prolonged litigation.
Key Takeaways
ACAS early conciliation is a mandatory procedural step before most employment tribunal claims can be submitted in England and Wales. Prospective claimants must notify ACAS of their intention to bring a claim, triggering early conciliation and pausing the statutory time limit. There are limited exceptions, including scenarios where another claimant has already conciliated the dispute or where ACAS lacks jurisdiction to conciliate the issue. While participation in substantive talks is voluntary, the notification requirement is central to preserving tribunal rights and managing time limits.
