In summary, you must submit your Acas early conciliation form within the normal time limit for bringing your tribunal claim (usually three months). This ‘stops the clock’ on that time period.
Time normally ‘stops’ for around four weeks (this can be extended by an extra two weeks if the Acas conciliator thinks a settlement is feasible in your case). The Acas conciliator uses this time to reach a negotiated settlement of the claim without the need to issue a claim in the employment tribunal. Neither side is obliged to engage with the Acas conciliator, but it is usually a good idea to take advantage of any opportunity to discuss settling the claim, as long as the terms on offer are fair and realistic. If you are not sure, speak to your union rep if you are a union member. Acas early conciliation is free and confidential.
Time starts running again as soon as Acas sends you an Acas Early Conciliation Certificate. This will have a reference number that you must use when issuing your tribunal claim. If, at this stage, there is less than one month left to issue your claim, you are given a minimum of one month from that date in which to do this.
Take care! - if the deadline is missed, the claim will be out of time and is likely to be dismissed.
Tribunals take a very strict approach to time limits. Take legal advice, for example from Citizens’ Advice, if you are at all unsure.