Employment tribunal time limits from 1 October 2026: six months, the transition date and what Acas conciliation adds

For years the first question on an employment intake call was "when did it happen?", because the answer decided whether there were three months or none. Since 1 October 2026 the same question has two answers. The time limit for most employment tribunal claims is now six months, but only for events on or after that date. Earlier events keep three months, and a firm that applies one rule to every file will get some dates wrong.

What changed and for which events

Section 152 and Schedule 12 of the Employment Rights Act 2025 raise the time limit for most tribunal claims in Great Britain from three months to six. The provisions came into force on 1 October 2026 under regulation 3 of SI 2026/954, subject to the transitional rules in regulation 4.

Regulation 4 says the new limit does not apply where the "relevant date" falls before 1 October 2026. The relevant date differs by type of complaint. For unfair dismissal it is the date employment ended. For other complaints it can be the date of the act complained about, or the last act in a series. So the test is the event, not the day the client first calls or the day the claim is filed.

GOV.UK now tells claimants they usually have six months from employment ending or the problem happening. That is the rule for new events; it does not undo the old limit for events already inside the transition.

Two dismissals one day apart

The usual way of counting is the period "beginning with" the date employment ended, which in practice ends on the corresponding date three or six months later, less one day. Where a date is close, count it the cautious way and file earlier.

The two deadlines are 92 days apart, for events one day apart. A client dismissed on 30 September who is told "you have six months" would miss the date by about three months.

What Acas early conciliation adds

A claimant must usually notify Acas and get an early conciliation certificate before claiming. Under section 207B of the Employment Tribunals Act 1996 two things follow. The days from the day after Day A (the day Acas is notified) to Day B (the day the certificate is received) are not counted. And if the limit would expire between Day A and one month after Day B, it expires one month after Day B instead.

Take Dismissal B. The claimant notifies Acas on 1 March 2027 and receives the certificate on 29 March 2027, 28 days later. The 31 March 2027 limit falls inside the period from Day A to one month after Day B, so it moves to 29 April 2027.

Acas notification has to be made inside the limit for any of this to help. Lodging with Acas on 1 April 2027 would be a day late for Dismissal B, and the extension would not rescue the claim.

A diary rule for the transition

1. Record the event date first. Put the date employment ended, or the date of the act complained about, at the top of the file. Do not record the date the client instructed you.
2. Write both limits down. Next to the event date, note which limit applies and the last day calculated under it. For anything dated 30 September or 1 October 2026, note the date counting rule you used.
3. Diary Acas notification as the real deadline. Claims fail on a late Acas notification more than on a late form, because the extension only works if Day A is in time.
4. Check the claim type. Equal pay and statutory redundancy payment claims were already at six months. Breach of contract claims moved by separate regulations, and a Scottish breach of contract claim has a different start date of 9 November 2026 according to one law firm's summary of those regulations, which we have not checked against the instrument itself.
5. Do not rely on a single series date. For a series of discriminatory acts the relevant date is the last one; whether the series is one is a legal judgement for the supervising solicitor.

Where this meets the rest of the file

A longer limit does not change the evidence problem: witnesses and documents age at the same speed. The client care letter checklist is where the event date and the deadline belong on a new matter. The Legal Ombudsman and tribunal clocks are different things, and the complaint deadline calculator shows how a firm's own complaint dates are counted. If an employment file turns into a probate or estate matter, the probate dates guide takes over the counting.

What we have not checked

We read the Act, the commencement regulations and the GOV.UK guidance. We did not read every limb of regulation 4, so a type of claim with an unusual relevant date should be checked against the instrument before the date goes in the diary. Case law on exactly how the final day of a limit is counted is not covered here.

Overlyft sets up an intake assistant that asks for the event date first, works out both limits and the Acas date from it, and puts them in the fee earner's diary for checking. A supervising solicitor reviews and signs anything a tool drafts or calculates. This page is general information, not legal advice.