What to expect from your employers ET3 response
If you’ve made a claim to the Employment Tribunal in the UK, you’re probably feeling a mix of emotions — anxious, hopeful, and maybe a little overwhelmed. One of the next big steps in the process is receiving your employer’s response, known as the ET3 form. Understanding what to expect can help you prepare and stay calm.
In this guide, we’ll walk you through what an ET3 response is, the common tactics employers use, and what legal terms like “vexatious,” “Polkey,” and “mitigation” actually mean — all in simple language.
What is the ET3 response?
Once you submit your claim (ET1 form) to the Employment Tribunal, your employer has 28 days to respond using the ET3 form. This form outlines their side of the story and explains why they disagree with your claim.
If you don’t receive the ET3 response on the 28th day do not cheer thinking your employer has not submitted one. Tribunal offices across the country suffer with huge backlogs and it can take several months for documents to be reviewed and passed along.
The ET3 response may feel formal and even harsh at times, but it’s important not to panic. It’s a legal document, so the language can be complicated, but we’ll break down the most common points for you.
The Grounds of Resistance: What your employer might say
The main section of the ET3 is called the “Grounds of Resistance.” This is where your employer sets out their reasons for defending the claim. Let’s go through the most common tactics and legal arguments they might use:
1. Denial of Your Claims
It’s very common for employers to simply deny everything in your ET1. They might say that the events you described didn’t happen, or that if they did happen, they weren’t unlawful.
For example:
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If you claimed unfair dismissal, they may argue you were dismissed for a fair reason — such as misconduct or redundancy.
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If you claimed discrimination, they might say the treatment you received wasn’t because of a protected characteristic like race, gender, or disability.
Don’t be discouraged — a denial doesn’t mean your claim is weak. It’s just the first step in their defence.
2. Denial of Knowledge
If you are claiming discrimination based on your disability, the employer may dispute you are actually disabled (by law) and/or they were unaware of your disability. An employer may also deny knowledge of other protected characteristics such as your sexual orientation.
In these cases, you should be prepared to offer evidence that either you have the protected characteristic and/or the employer was fully aware.
3. Threatening to Claim Costs
Your employer may mention in the ET3 that they intend to ask for costs if they believe your claim is “frivolous” or “vexatious.”
What does this mean?
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A frivolous claim is one with no serious purpose.
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A vexatious claim is one made to harass or annoy the employer.
This can sound scary, but costs are rarely awarded in Employment Tribunals. The bar is high — only claims with absolutely no chance of success are at risk of costs orders. If you’ve brought your claim honestly and with a reasonable argument, this is usually an empty threat.
4. Calling Your Claim Unfounded, No prospect of success, or Frivolous
Sometimes, employers will use strong language to make you doubt your case. They might accuse you of making a claim just to “get back” at them or to waste their time.
Again, don’t let this shake you. The Tribunal is used to seeing these claims and will decide for themselves whether your case has merit.
5. Requesting Better Particulars
Your employer might ask you for “better particulars” of your claim. This means they want more detail about what happened — for example, the exact dates of incidents, who was involved, or how you calculated any compensation you’re asking for.
This isn’t a bad thing! It’s part of the legal process, and it can actually help sharpen your case. The Tribunal might ask you to clarify your points, but this doesn’t mean your case is weak.
Legal arguments within the ET3
In addition to the above tactics, employers often use specific legal defences. Let’s break down three of the most common ones:
1. The Polkey Argument
Your employer may refer to the Polkey deduction. This comes from a legal case (Polkey v AE Dayton Services Ltd) and means that even if the employer did dismiss you unfairly, they might argue you would have been dismissed anyway for a fair reason.
For example:
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You hit a fellow employee in the face and everyone saw. You were dismissed on the spot. Although this could have been an unfair dismissal because no procedure took place, if a proper procedure had taken place you would have undoubtedly been dismissed for the gross misconduct anyway.
If the Tribunal agrees, any compensation you receive could be reduced.
2. The Chagger Principle
Your employer might also mention the Chagger case (Chagger v Abbey National plc). This is often used in discrimination claims.
Under Chagger, if you prove discrimination led to your dismissal, your employer might argue that even without discrimination, you would have still lost your job — just for another reason. Again, this can reduce compensation.
3. Failure to Mitigate Losses
Your employer might argue you failed to “mitigate your losses.” This means they could claim you didn’t try hard enough to find a new job after being dismissed and therefore your claim for compensation is unreasonable.
To counter this, keep records of job applications, interviews, and any rejections. This shows the Tribunal you’ve been actively looking for work.
How to stay calm and prepare
Reading an ET3 response can feel personal and upsetting. But remember:
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It’s a legal document — expect formal language and strong denials.
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Tactics like threats of costs or calling your claim vexatious are often just bluster.
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You have the right to stand your ground. Your claim was accepted by the Tribunal for a reason.
What can you do next?
DO NOT RESPOND TO THE ET3
The employment tribunal is not a ‘trial by email’. Whilst it’s tempting to reply and correct any mistakes, disprove lies or shout back, it is highly advised not to. Anything you write or provide in response could be used against you and/or give the employer an unfair advantage.
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Get support — from a solicitor, a union rep, the Sue My Employer Coaching or organisations like ACAS or Citizens Advice.
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Stay organised — keep all documents, emails, and evidence safe. Now you have a better understanding of your employer’s defence, consider what you can present to counter this.
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Prepare for what’s next — the Tribunal may ask you for more details, but that’s normal. You only need to respond to the ET3 following a judge’s orders, not before.
