This page references a confirmed change to Employment Tribunal time limits taking effect on 1 October 2026 — always check GOV.UK for the current position before relying on a specific deadline.
Introduction
Working out your exact deadline matters more than almost anything else in bringing a claim. Get it wrong, and a highly meritorious case can be thrown out before it’s even heard. This guide works through the calculation step by step. It covers the part that trips up most people: how ACAS Early Conciliation actually affects your real deadline.
Table of Contents
- Employment Tribunal Claim Time Limit Calculator
- The Standard Rule: Three Months Less One Day
- Working Out Day One
- How ACAS Early Conciliation Changes the Calculation
- A Worked Example
- What If Your Deadline Falls on a Weekend?
- Using an Employment Tribunal Claim Time Limit Calculator Properly
- Common Calculation Mistakes
- Different Time Limits for Different Claims
- Why This Calculation Catches People Out
- Contact Us for Employment Tribunal Support
- Final Thoughts
- Frequently Asked Questions
Employment Tribunal Claim Time Limit Calculator
Employment Tribunal Support
Employment tribunal claim
time limit calculator
Work out your realistic deadline, including how ACAS Early Conciliation pauses and extends the standard three-month time limit.
Your calculated deadline
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How this was worked out
Note on weekends and bank holidays: Employment Tribunal deadlines are not shifted to the next working day if they fall on a weekend or bank holiday, unlike some civil court deadlines. Online submission remains open until midnight on the date itself.
The Standard Rule: Three Months Less One Day
Most Employment Tribunal claims must be started within three months less one day of the relevant date. That’s not quite the same as “three months.” Subtracting one day matters, and it’s a common source of confusion right from the start.
The relevant date is usually your dismissal date, or the date of the act you’re complaining about. For a continuing situation, it’s usually the last date in that pattern of conduct.
Working Out Day One
Day one of the three-month period is the day after the relevant date, not the relevant date itself. Under established tribunal rules (Dodds v Walker), the three-month period ends on the corresponding numerical date in the third month, minus one day. If you were dismissed on 10 January, three months later is 10 April; subtract one day, and your actual deadline is 9 April.
This small shift matters. Getting the starting point wrong by even a single day can push your whole calculation out of line.
How ACAS Early Conciliation Changes the Calculation
Before you can bring most claims, you need to notify ACAS and go through Early Conciliation. This process pauses your deadline while it’s running, using two key dates.
Day A is the date ACAS receives your Early Conciliation notification. Day B is the date you receive your Early Conciliation certificate. The period between Day A and Day B doesn’t count toward your three months. It gets added back onto your original deadline instead.
A second rule matters too. Sometimes your adjusted deadline still falls within one month of Day B. In that situation, the law extends it further. Your deadline becomes exactly one month after Day B, whichever date gives you the longer period.
A Worked Example
Say you were dismissed on 10 January. Your standard deadline, before ACAS involvement, is 9 April. You contact ACAS on 1 March (Day A) and receive your certificate on 15 March (Day B).
The pause period added to your deadline is 14 days. Adding 14 days to your original 9 April deadline gives you 23 April. Now check the second rule: one month after Day B (15 March) is 15 April. Since 23 April is later than 15 April, your final deadline is 23 April.
Change the numbers slightly, and the answer changes too. If your certificate had arrived close to your original deadline instead, the one-month extension would likely take over. It would give you more time than the simple pause calculation alone.
What If Your Deadline Falls on a Weekend?
This trips people up more than almost anything else, partly because civil court deadlines work differently. In the ordinary civil courts, a deadline landing on a weekend or bank holiday usually shifts to the next working day.
Employment Tribunal deadlines don’t follow that same rule. The Employment Appeal Tribunal confirmed this directly in Miah v Axis Security Services Ltd, finding that a claim received the day after a deadline falling on a Sunday was genuinely out of time. The tribunal’s online submission system runs continuously for exactly this reason. If your deadline falls on a Sunday or a bank holiday, that date still stands, and you can submit right up until midnight that day.
Don’t leave submission until the final hours regardless. Technical problems on the day itself won’t excuse a late claim, whatever the underlying reason.
Using an Employment Tribunal Claim Time Limit Calculator Properly
Given how many rules interact here, working everything out by hand close to your deadline carries real risk. A proper employment tribunal claim time limit calculator, whether that’s a structured manual method or a dedicated tool, needs to account for all of it: the day-one shift, the ACAS pause, the one-month backstop, and the fact that weekend deadlines aren’t extended. Missing any single piece changes your final answer, sometimes by weeks.
Common Calculation Mistakes
A few errors show up again and again. People forget to subtract the extra day, landing on the wrong date by exactly one day. People also miscount the ACAS pause, sometimes using the wrong Day A or Day B date, or forgetting the one-month extension rule entirely. Others assume raising an internal grievance pauses their deadline. It doesn’t. Only a valid Early Conciliation notification actually stops the clock.
Working this out on paper close to your deadline is genuinely risky. Check your own dates well before time runs short, rather than relying on a rough estimate.
Different Time Limits for Different Claims
Not every claim follows the same three-month rule. Equal pay claims commonly run to six months less one day from the end of employment instead. The standard three-month limit is also changing more broadly. From 1 October 2026, most claims move to a six-month time limit under the Employment Rights Act 2025. This only applies to events occurring on or after that date, though, so it’s not yet relevant for most current claims.
Once your deadline is confirmed, completing your claim form correctly is the next practical step, and getting the timing right first avoids submitting too early or too late.
Why This Calculation Catches People Out
The core problem is that this isn’t one simple calculation. Several rules layer on top of each other: the basic three-month period, the day-one adjustment, the ACAS pause, the one-month backstop, and the fact that weekends don’t shift the deadline. Missing any single layer changes your answer. Genuinely strong claims have been lost purely on timing, regardless of how solid the underlying facts were.Contact Us for Employment Tribunal Support
If you’re at all unsure about your own deadline, get it checked rather than relying on a manual calculation close to the wire.
Final Thoughts
Calculating your deadline properly protects something you genuinely can’t get back once it’s gone. The three-month rule, the day-one adjustment, the ACAS Day A and Day B mechanics, and the weekend rule all interact with each other. Getting any one piece wrong can cost you the right to claim at all. When in doubt, check early, not close to the date you think is correct.
Frequently Asked Questions
What is the standard employment tribunal time limit?
Three months less one day from the relevant date, usually your dismissal date or the date of the act you’re complaining about.
How does ACAS Early Conciliation affect my deadline?
It pauses the clock between Day A, when ACAS receives your notification, and Day B, when you receive your certificate. That paused period gets added back onto your original deadline.
What is the one-month extension rule?
If your deadline, once adjusted for the ACAS pause, would still fall within one month of receiving your certificate, the law extends it to exactly one month after that certificate date instead.
Does my deadline shift if it falls on a weekend or bank holiday?
No. Unlike the civil courts, Employment Tribunal deadlines aren’t automatically extended to the next working day, as confirmed by the Employment Appeal Tribunal. Online submission remains available right up until midnight on the actual deadline.
Does raising a grievance pause my deadline?
No. Only a valid Early Conciliation notification to ACAS pauses the clock. An internal grievance or appeal doesn’t affect the tribunal deadline at all.
Are all employment tribunal time limits three months?
No. Equal pay claims commonly run to six months less one day instead, and the standard three-month limit is itself changing to six months for events from 1 October 2026 onward.




