Time Limits for Unfair Dismissal | When EDT time starts and how to extend it ?

William Slivinsky
Sep 13
5 min read

When does the clock start running — and can it be extended ?UDO explains the most important considerations to extend the time.

If you also have other claims, remember: unfair dismissal may stand alone, but claims like discrimination, equal pay, or whistleblowing often cover longer periods of conduct. These claims may have different time limits, and in most cases employers will argue that they are time-barred. We explain extensions for those claims in another article.

This article guides you on how to properly establish when the clock starts — the Effective Date of Termination (EDT) and how tribunals decide it. In another article, we explain when and how the clock can stop during Acas Early Conciliation, and what that means for your deadline.

Time Limits for Unfair Dismissal - What is the Effective Date of Termination (EDT) ?

The Effective Date of Termination (EDT) is the starting point for almost everything in an unfair dismissal case. It decides:

How long you have to bring your claim – unfair dismissal claims must be made within three months less one day of the EDT.
Whether you have enough continuous service – for example, if you worked 23 months but your contractual notice was one month, tribunals count that notice period. You reach the two-year requirement for unfair dismissal. This applies for qualifying service and the basic award, but ❌ not for time limits.
How compensation is worked out – the basic award is based on your length of service up to the EDT, and the compensatory award is calculated from losses flowing after that date.

Unfair Dismissal and Section 97 ERA 1996

Under section 97 ERA 1996:

If you’re given notice → the EDT is the day the notice period ends.
If you’re dismissed without notice → the EDT is the day the dismissal takes effect.

But section 97 does not explain what “takes effect” means. Case law filled the gap:

Brown v Southall, McMaster v Manchester Airport – dismissal is not effective until the employee knows about it.
Haywood v Newcastle, Gisda Cyf v Barratt – the EDT is when the employee reads the letter or has a reasonable opportunity to do so, not when it was written or sent.

The Time Limit Rule

The standard time limit for an unfair dismissal claim is three months less one day from the EDT (s.111 ERA 1996). This can be extended by at least one month if Acas Early Conciliation is started and the original deadline falls during that process. 👉 But without taking Acas conciliation into account, if your EDT is 1 August, the deadline is 31 October.

When is the EDT?

Tribunals decide the EDT by looking at when the dismissal actually takes effect and when it was communicated.

If you are told in a disciplinary hearing on 1 August that dismissal takes immediate effect, the EDT = 1 August.
If you are told on 1 August that dismissal will take effect from 7 August, the EDT = 7 August.
If you are told you will be notified later, and you receive a dismissal letter on 30 August backdated to 1 August, the EDT = 30 August.
If you only find out on 15 September after enquiring yourself, the EDT = 15 September, even if your P45 says 1 August.
⚖️ If your employer claims you were told during the hearing, but the minutes of that meeting don’t support it, you can argue the EDT is the date you received the dismissal letter, not the earlier date asserted by the employer.

Can the Time Limit Be Extended?

Yes — but only in specific circumstances:

Unfair dismissal claims: Tribunal may extend if it was “not reasonably practicable” to claim in time.
Discrimination and other claims: Tribunal may extend if it is “just and equitable” to do so.

⚖️ The “not reasonably practicable” test is much stricter. Don’t rely on it if you can avoid it by proper calculation of EDT. 👉 For full guidance, see our separate article on late claims and extensions of time.

Special Rules That Affect the EDT

Statutory minimum notice
Failure to give notice extends continuous service and the basic award, but ❌ does not extend the tribunal time limit.
Communication matters
EDT = when you know you are dismissed. If you don’t open a letter or email, EDT is when you read it — unless you deliberately avoid it.
P45s mislead
The date on a P45 is irrelevant. Tribunals rely on actual communication of dismissal. (Leech v Preston BC; Kelly v Riveroak).
Third-party messages
EDT is when the employee is told, not when the employer passes the message to someone else. For example, if the employer passed your dismissal to you firend on 1 August but the friend tolnd you of your dismissal on 1 September, the EDT is 1 September.
Acas Early Conciliation
Tribunal time limits are paused during conciliation, and you get at least an extra month after it ends.

Case Examples

📌 Example 1 — Clear communication

Dismissed on 1 August at a hearing. Letter arrives on 7 August. EDT = 1 August. Deadline: 31 October.

📌 Example 2 — Email not opened

Dismissed on 15 October by email. Employee opens it on 20 November after illness. EDT = 20 November.

📌 Example 3 — Wrong P45 date

Dismissed on 20 March at a hearing. P45 wrongly says 1 May. EDT = 20 March.

📌 Example 4 — Message passed late

Dismissed on 28 February. Employer told a friend to pass on the dismissal. Employee only hears it on 15 June. EDT = 15 June.

📌 EDT vs Extension of Time

EDT = when dismissal takes legal effect (s.97 ERA 1996 + case law).
If you didn’t know you were dismissed → EDT moves to when you found out.
Extension = if you knew the EDT but still couldn’t claim in time, you must show it was not reasonably practicable to claim earlier (s.111 ERA 1996).

Practical Tips

Record the date you were told about your dismissal — this is usually your EDT.
❌ Don’t rely on P45s or payroll dates.
✅ Use Acas Early Conciliation to freeze time limits if needed.
If you miss the deadline, you must prove it was not reasonably practicable. That’s a high bar — act early.

Key Takeaway

The EDT is about when dismissal is communicated to you, not the date written on the letter or form. Get your dates right, and you protect your claim. Get them wrong, and you risk being out of time.

Calculating the correct EDT is also the key to working out how Acas Early Conciliation stops the clock — either by pausing it for the conciliation period or, if your original deadline would have expired during that time, by giving you at least one extra month.

👉 Next step: UDO explains how to calculate the Acas period and apply it to your deadline.