Employment Tribunal Time Limit and ACAS Early Conciliation Calculator

How to do it

1. 1
   Enter the date of the event

   For a dismissal use the effective date of termination.

2. 2
   Choose the time limit

   Three months, or six months if the new rule applies to your claim.

3. 3
   Enter the ACAS dates

   Type Day A and, when you have it, Day B.

4. 4
   Read the deadline

   See the last day and how the extension was worked out.

5. 5
   Act

   Contact ACAS or an adviser immediately.

About this tool

Most employment tribunal claims must be made within three months less one day of the event you complain about, such as a dismissal. Before you claim, you usually have to notify ACAS to start early conciliation, and this pauses the clock. This calculator takes the date of the event, the date ACAS received your notification (Day A) and the date the early conciliation certificate was issued (Day B), and shows the deadline, the way the extension works and the days left. Because the law is changing the time limit for some claims, you can choose a limit of three or six months.

Who this is for Employees who have been dismissed, treated unfairly or discriminated against and who want to check their deadline, and advisers who need a quick calculation. It is not legal advice, and missing the deadline can end a claim.

The primary time limit For most claims, including unfair dismissal, discrimination and unlawful deduction from wages, the claim form must be received within three months less one day from the date of the event. For a dismissal, the date is the effective date of termination. If the event was on 14 August, the limit is 13 November. Time limits for redundancy payments and some other claims are different. The Employment Rights Act 2025 extends the time limit for many claims to six months, to take effect from a date set by regulations, so you can choose six months in the tool if your claim falls under the new rule.

ACAS early conciliation Before you can bring most claims, you must contact ACAS. The day ACAS receives your notification is Day A. The day ACAS issues the certificate is Day B. The time between Day A and Day B does not count toward your limit. After Day B you have at least one month to present the claim.

How the extension works If the normal time limit would expire between Day A and one month after Day B, the new deadline is one month after Day B. If the normal limit would expire later than that, you add the number of days between Day A and Day B to the original deadline. If you notify ACAS after the normal limit has passed, early conciliation does not extend the time, which is a trap. The tool shows which case applies.

Worked example An event on 14 August 2026 gives a primary limit of 13 November. ACAS is notified on 1 September and the certificate is issued on 1 October. The normal limit is later than one month after Day B (1 November), so 30 days are added and the deadline is 13 December 2026. If ACAS is notified on 2 November and the certificate issues on 20 November, the original limit falls inside the process, so the deadline is one month after Day B, 20 December 2026.

Late claims A tribunal can accept a late claim only if it was not reasonably practicable to bring it in time, and then within a reasonable period, or, for discrimination claims, if it is just and equitable. These tests are strict, so do not rely on them.

Limits This calculator is a date tool and not legal advice. Check the current rules on GOV.UK and contact ACAS or a lawyer as soon as possible.

Worked example

For an event on 14 August 2026 with ACAS notified on 1 September and the certificate on 1 October, the deadline moves from 13 November to 13 December 2026.