ACAS Early Conciliation Has Failed
If ACAS early conciliation does not resolve your employment dispute, you will receive a certificate that allows you to proceed to the employment tribunal. You must file your ET1 claim before your recalculated deadline.
Quick Answer
When ACAS issues an early conciliation (EC) certificate, the clock on your tribunal deadline is unfrozen. Your new deadline is either your original deadline extended by the conciliation period, or one month from the date on the certificate, whichever is later. You must file your ET1 before that date โ there is very little discretion to extend it.
Full Explanation
Mandatory early conciliation was introduced by the Enterprise and Regulatory Reform Act 2013 and came into force under s.18A of the Employment Tribunals Act 1996. Before submitting an ET1 to the employment tribunal, a claimant must first notify ACAS. ACAS then contacts the other party to see if conciliation can resolve the matter.
The conciliation period lasts up to six weeks. During that time, your limitation period is frozen โ time stops running. When the conciliation period ends (whether because agreement has been reached, either party opts out, or the six weeks expire without resolution), ACAS issues an EC certificate. This certificate is essential: you cannot file an ET1 without quoting the EC certificate number.
The effect on your limitation deadline is set out in s.140B of the Employment Tribunals Act 1996. In broad terms, the period between contacting ACAS and receiving the EC certificate is added to your limitation period (the 'Day B minus Day A' calculation), but the minimum extension is one month from the date on the certificate.
Once the certificate is issued, act quickly. Employment tribunal deadlines are treated very strictly โ courts have found that being one day late is fatal, even if the delay was caused by a postal error. File the ET1 online at employment-tribunals.service.gov.uk using the EC certificate number. The tribunal will acknowledge receipt and then serve the ET1 on the respondent.
Even after the EC certificate is issued and the ET1 is filed, settlement remains possible. ACAS conciliation officers remain available throughout tribunal proceedings under s.18 of the Employment Tribunals Act 1996. Many cases settle at the stage of the ET3 response or at a preliminary hearing โ do not close the door on negotiation just because formal proceedings have started.
Legal Basis
- ยงEmployment Tribunals Act 1996, s.18A (mandatory early conciliation)
- ยงEmployment Tribunals Act 1996, s.140B (effect on limitation periods)
- ยงEnterprise and Regulatory Reform Act 2013 (introducing mandatory ACAS notification)
- ยงEmployment Tribunal Procedure Rules 2013 (SI 2013/1237)
What To Do
Receive and Check Your EC Certificate
When ACAS issues the EC certificate, check the dates carefully. The certificate will show the day you contacted ACAS (Day A) and the date the certificate was issued (Day B). Calculate your adjusted deadline using the Day B minus Day A formula โ your original deadline is extended by that number of days, subject to a minimum one-month extension.
Calculate Your Adjusted Limitation Deadline
For most claims, the basic limitation period is three months less one day from the act complained of. Add to this the number of days between Day A and Day B (the conciliation period). Compare this to one month from the certificate date and use whichever is later.
File Your ET1 Online Before the Deadline
Go to employment-tribunals.service.gov.uk and complete the ET1 form online. You will need your EC certificate number. Be precise about the acts complained of and the legal basis (unfair dismissal, unlawful deduction from wages, discrimination, etc.). Do not leave the filing to the last day โ if there are technical problems, you need time to call the tribunal helpline.
Keep Settlement Talks Open
Filing the ET1 does not mean you cannot settle. Continue to engage constructively with the employer or their representatives. ACAS conciliation officers remain available to facilitate settlement at any stage of the tribunal proceedings.
Important Deadlines
Important Warnings
Employment tribunal limitation deadlines are applied very strictly โ arriving one day late will usually bar your claim entirely; file well before the deadline.
The EC certificate number is mandatory on the ET1 โ you cannot submit the claim form without it.
If conciliation was genuinely productive but more time is needed, ACAS can facilitate further discussions under s.18 after the ET1 is filed โ you do not have to break off negotiations just because the certificate has been issued.