Unfair Dismissal Time Limits – Using the “Not Reasonably Practicable” Route (s.111 ERA 1996)

Unfair dismissal time limit extended because "not reasonably practicable" (NRP) — s.111 ERA 1996. How and when you can get the time limit extended ?

This is Part 3 of our Time Limits series.

• Part 1 – Start the clock (EDT): work out when time starts.

• Part 2 – Stop the clock (Acas): see when and how the time pauses.

  
  

  Part 3 (this page) – Still late? Use the NRP route.

Only use NRP after you’ve done EDT and Acas. Many “late” claims aren’t late once you apply those two.

Why this matters

You should only consider the “not reasonably practicable” (NRP) route after you have worked out your Effective Date of Termination (EDT) and applied the ACAS stop-the-clock rules. Many claims that first appear late are actually still in time once those two steps are done correctly.

If, after those steps, you are still outside the 3-month limit, the next question is whether you can show it was not reasonably practicable to present your claim earlier.

⚠️ Important: UDO does not advise waiting until you work out whether NRP applies. The rule is simple: as soon as you realise you are out of time, submit your claim immediately. The tribunal will then consider your NRP argument while your claim is pending.

Different rules for discrimination claims

So far, I’ve been talking about unfair dismissal. The rules for discrimination are not the same. For unfair dismissal, you only get an extension if it was not reasonably practicable to put your claim in on time. That’s a strict test — the tribunal looks at whether you could, with reasonable effort, have managed it.

For discrimination, the tribunal can extend time if it is just and equitable to do so. That’s a wider, more flexible test. The tribunal looks at fairness overall — why the claim is late, how long the delay was, whether evidence is still fresh, and how each side would be affected.

In simple terms:

• Unfair dismissal → “reasonably practicable” (strict, narrow, hard to extend).

• Discrimination → “just and equitable” (broader, more flexible, better chance if late).

  
  

This is important because many dismissals are also linked to discrimination. If you are out of time, it may be better to plead both unfair dismissal and discrimination (where facts allow) rather than unfair dismissal alone. In Mr Pora’s case, the unfair dismissal claim was out of time, but the linked discrimination claim was allowed to go forward.

The Legal Framework – ERA 1996, s.111(2)

An Employment Tribunal shall not consider a complaint of unfair dismissal unless it is presented—

• (a) within three months of the effective date of termination, or

• (b) within such further period as the tribunal considers reasonable, where it is satisfied that it was not reasonably practicable for the complaint to be presented before the end of the three-month period.

What this post covers

In this part of the series, UDO gives you clear, practical guidance on what “not reasonably practicable” means, how tribunals apply the test, and what circumstances may or may not succeed. Each point is illustrated with case law summary and analysis, which you can explore through the links provided.

Index of key grounds for “not reasonably practicable”Click on each title below to go to the relevant section.

→ Misadvised by ACAS, CAB, a union representative, or another non-skilled advisory organisation or firm, but only availabe when advice is given by no skilled adviser.

Misadvice and Late Claims

One of the most common reasons employees give for a late claim is misadvice. Another is simply not knowing there was a time limit. Let’s be clear: just saying you didn’t know will almost never be enough. A tribunal expects you to make some effort — to check with ACAS, Citizens Advice, your union, a law centre, or a solicitor. If you did nothing, the tribunal will usually decide it was reasonably practicable for you to find out in time. The only real exception is where something outside your control, like serious illness, genuinely prevented you from seeking advice.

Misadvice is different. This is where someone did take a reasonable step — they asked a recognized body such as ACAS, CAB, or a union — but the information given turned out to be wrong. In that situation, the tribunal may accept that it was not reasonably practicable to present the claim in time. But there are still conditions: you will need to show who gave the advice, what was actually said, and that you acted quickly once you discovered the mistake. But importantly, even though this may be an organization, you must make sure the adviser is not seen as a skilled adviser → check their definition.

The case of Mrs Sieradzka illustrates how tribunals handle these situations and what kind of evidence can make a difference. I have set out the key points from that case with practical takeaways you can use.

Go to → Paczkowski v Sieradzka 

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Terms expained

Skilled adviserA skilled adviser is someone formally qualified or authorised to provide legal advice in a professional capacity. This includes solicitors, barristers, paralegals working in law firms or legal departments, licensed paralegals (for example, those accredited by NALP with a licence to practise), and paralegals with a minimum of three years’ experience in a specialist area of law. It also covers trained union legal officers.

If you relied on advice from a skilled adviser and it turned out to be wrong, the tribunal will usually say you are bound by that mistake. In other words, their error is treated as your error. This makes it a very poor ground for arguing that it was “not reasonably practicable” to bring your claim late. Claims based on misadvice from skilled advisers rarely succeed — the tribunal expects that when you formally instruct a professional, you accept the risk of their mistakes.

If that is the case, and your skilled adviser’s mistake caused you to miss the time limit, the tribunal will treat it as a matter between you and the adviser (for example, a potential complaint or claim against them), not as a ground for extending the time limit for your tribunal claim.

However, it is not always the case. There is still a thin chance of succeeding, and I explain one example of that above in the main article.

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Non-skilled adviserA non-skilled adviser is someone who offers general help or guidance but is not formally qualified or authorised to provide professional legal advice. This usually includes organisations like ACAS helplines, Citizens Advice, union representatives without legal training, law centre volunteers, or community advisers. Friends, family members, or colleagues giving informal advice also fall into this category.

If you relied on misadvice from a non-skilled adviser and that caused you to miss the time limit, the tribunal may accept this as a ground for arguing it was “not reasonably practicable” to bring your claim on time. The key is whether you acted reasonably in turning to that source of help, what exactly was said, and how quickly you acted once you discovered the mistake.

It is very unlikely that the tribunal will find it reasonable if you relied only on advice from a friend or neighbour with no relevant knowledge — for example, someone working as a builder who once went through a tribunal case themselves. By contrast, you may be in a stronger position if the friend had some relevant background, such as HR training, even if they were not a formally qualified legal adviser.

This is why cases like Sieradzka are important: they show how tribunals look closely at who advised you, what advice was given, and whether you can prove it. Unlike misadvice from skilled advisers, which rarely succeeds, misadvice from non-skilled advisers can sometimes be a strong ground — provided you have clear evidence and acted promptly.