Employment Tribunal Time Limits Calculator

Calculating your employment tribunal time limit is one of the most critical steps when considering a claim against your employer. Get it wrong and you could lose your right to bring a claim entirely, regardless of how strong your case might be.

A time limits calculator can help you work out your deadline, but the calculation involves several moving parts: your primary time limit, the early conciliation period, and minimum guarantee rules. In our experience, even legally advised claimants sometimes miscalculate these dates, which is why understanding the underlying rules matters as much as the arithmetic.

How Employment Tribunal Time Limits Work

Employment tribunal time limits are strict. Under section 111 of the Employment Rights Act 1996, unfair dismissal claims must be presented within three months beginning with the effective date of termination. Similar provisions apply to discrimination claims under section 123 of the Equality Act 2010.

The phrase “three months minus one day” trips people up. If you were dismissed on 15 March, your time limit expires at 11:59pm on 14 June, not 15 June. You add three calendar months to the relevant date, then subtract one day.

The following table sets out the primary time limits for different claim types:

Claim Type	Primary Time Limit	Starting Point
Unfair dismissal	3 months minus 1 day	Effective date of termination
Discrimination	3 months minus 1 day	Date of the discriminatory act
Unlawful deduction from wages	3 months minus 1 day	Date of deduction (or last in series)
Breach of contract	3 months minus 1 day	Date of termination
Statutory redundancy pay	6 months minus 1 day	Relevant date
Equal pay	6 months minus 1 day	Date of termination

The Early Conciliation Clock Extension

Before you can submit a claim to the employment tribunal, you must first notify Acas and go through early conciliation. This requirement was introduced in 2014, and the rules for how it affects your time limit are set out in section 207B of the Employment Rights Act 1996.

The key dates you need to know are Day A and Day B:

• Day A is the day you contact Acas to start early conciliation
• Day B is the day you receive your early conciliation certificate

Section 207B operates in two ways. First, under subsection (3), the period between Day A and Day B does not count when calculating your time limit. The clock effectively stops. Second, under subsection (4), if your original time limit would expire between Day A and one month after Day B, it is automatically extended to one month after Day B.

The Employment Appeal Tribunal confirmed in Luton Borough Council v Haque [2018] UKEAT/0180/17 that these two provisions work cumulatively, not as alternatives. You apply subsection (3) first, then check whether subsection (4) gives you any additional time.

How to Calculate Your Extended Time Limit

Follow these steps to work out your final deadline:

Step 1: Identify your starting date (the event giving rise to your claim)

Step 2: Calculate your primary time limit by adding 3 months and subtracting 1 day

Step 3: Count the days between Day A and Day B (inclusive of Day B)

Step 4: Add those days to your primary time limit. This is your new deadline under subsection (3)

Step 5: Check whether your original primary time limit fell between Day A and one month after Day B. If so, you get at least until one month after Day B

Step 6: Your final deadline is whichever date is later

Worked Example

Consider this scenario: Sarah was dismissed on 15 June 2026. She contacted Acas on 1 September 2026 (Day A) and received her certificate on 25 September 2026 (Day B).

Primary time limit: 15 June 2026 + 3 months = 15 September 2026, minus 1 day = 14 September 2026

Days in early conciliation: 1 September to 25 September = 24 days

Extended deadline under s.207B(3): 14 September 2026 + 24 days = 8 October 2026

Check s.207B(4): The original deadline (14 September) fell between Day A (1 September) and one month after Day B (25 October). So Sarah is guaranteed until 25 October 2026.

Final deadline: 25 October 2026 (the later of the two dates)

The 12-Week Early Conciliation Period (From December 2025)

From 1 December 2025, the maximum early conciliation period increased from 6 weeks to 12 weeks. This change was introduced by the Employment Tribunals (Early Conciliation: Exemptions and Rules of Procedure) (Amendment) Regulations 2025 and applies to all conciliation notifications made on or after that date.

The extension means claimants potentially have longer before their final deadline, but it also means a longer period of uncertainty for both parties. If you started early conciliation before 1 December 2025, the old 6-week maximum still applies to your case.

The “stop the clock” rules remain unchanged. Whether conciliation lasts 2 weeks or 12 weeks, that entire period does not count towards your time limit.

October 2026: Time Limits Extending to 6 Months

The Employment Rights Act 2025 will extend most employment tribunal time limits from 3 months to 6 months. According to Acas guidance, this change takes effect in October 2026.

Once in force, the new 6-month limit will apply to claims where time starts running on or after the implementation date. Claims with earlier start dates will still follow the current 3-month rules.

Combined with the 12-week early conciliation period, claimants could potentially have up to 9 or 10 months from the relevant event before their final deadline expires. Employers should be aware that this extends the period of uncertainty and requires longer document retention.

What If You Miss Your Deadline?

Missing your time limit does not automatically mean your claim is dead, but the barriers to proceeding are high. Tribunals can extend time limits, but only in limited circumstances depending on the type of claim.

The “Not Reasonably Practicable” Test

For unfair dismissal and most statutory employment rights claims, the tribunal can only extend time if you can show it was “not reasonably practicable” to present your claim in time, and that you then submitted it within a reasonable further period.

This is a strict test. Tribunals have held that ignorance of your rights is not usually a good excuse if you could have discovered them with reasonable diligence. Being aware of time limits but miscalculating them rarely succeeds either.

The “Just and Equitable” Test

For discrimination claims under the Equality Act 2010, tribunals have broader discretion. Under section 123(1)(b), they can extend time if they consider it “just and equitable” to do so. This involves weighing all relevant factors, including the length of the delay, reasons for it, potential prejudice to each party, and the merits of the claim.

Recent case law has clarified that even without a detailed explanation for the delay, a tribunal must still consider whether an extension is just and equitable. In Owen v Network Rail Infrastructure Ltd, the EAT held that absence of evidence explaining the delay is not automatically decisive.

That said, there is no presumption in favour of extending time. The burden remains on the claimant to persuade the tribunal that an extension is warranted.

Common Mistakes We See

In our experience, several errors crop up repeatedly:

Waiting for internal processes to conclude. Going through grievance or appeal procedures does not pause your tribunal time limit. Many claimants assume they must exhaust internal processes first, then find themselves out of time. You can and should notify Acas while internal procedures are ongoing.

Confusing the event date with the communication date. Time usually runs from when a decision was made, not when you were told about it. In discrimination claims involving recruitment decisions, for example, time may start running before the employer communicates the outcome to you.

Relying on verbal reassurances. Statements from employers or colleagues about timing carry no legal weight. Only the statutory time limits and your Acas certificate dates matter.

Not accounting for weekends or bank holidays. Your deadline is your deadline, whether it falls on a Sunday, Christmas Day, or any other day. The tribunal’s online system operates 24/7, but if you leave submission to the last day, technical problems could prevent you from meeting it.

Starting early conciliation before employment ends. If you contact Acas before your termination date, only the portion of the conciliation period after termination counts towards extending your unfair dismissal time limit. The EAT confirmed this in Raison v DF Capital Bank Ltd [2024].

Practical Tips for Getting Your Timing Right

Start early. Contact Acas as soon as you know there is a potential claim, even if you are still employed or hoping matters will resolve. Early conciliation is free, confidential, and gives you time to consider your options without the clock running down.

Keep records of all key dates: your termination date, the date you contacted Acas, and the date your certificate was issued. These are the inputs for any time limits calculator.

Build in a safety margin. Aim to submit your claim at least a week before your calculated deadline. This protects you against technical issues, postal delays (if using paper forms), or any last-minute complications.

Seek legal advice promptly. Employment solicitors deal with time limit calculations daily and can provide certainty about your deadline. A short initial consultation could save your entire claim.