What is the deadline for et1 unfair dismissal?
An unfair dismissal claim must usually reach the Employment Tribunal within three months less one day from the effective date of termination. ACAS Early Conciliation can change the final date.
Calculate your deadline
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Worked example
- Example input
- 03/08/2026
- Expected result
- Monday 2 November 2026
Employment ended on Monday 3 August 2026, before any ACAS adjustment.
The ordinary three-months-less-one-day period ends on 2 November. The effective termination date and ACAS Early Conciliation dates must be correct.
How this deadline is counted
- Period
- Three calendar months less one day
- Trigger
- Effective date of termination
- Direction
- Forward from the effective date of termination
- Counting method
- Calendar months, then subtract one day
The calendar-month calculation preserves the corresponding date where possible. The calculator shows any resulting month-end treatment.
Employment Rights Act 1996, section 111. Employment Rights Act 1996, section 111. Employment Tribunal Procedure Rules 2024 and cited statute checked 06/08/2026
Exceptions and matter facts
- ACAS Early Conciliation changes the calculation and requires the Day A and Day B dates.
- A tribunal may consider a late claim where it was not reasonably practicable to present it in time and it was then presented within a reasonable period.
Deadline Engine is calculation software, not legal advice. Check the current rule, any order and the facts before adding a date to your diary.