Employment Tribunal Response UK: ET3 Form Guide

At a glance

• Current rules: the Employment Tribunal Procedure Rules 2024 (SI 2024/1155) apply from 6 January 2025, replacing the Employment Tribunals (Constitution and Rules of Procedure) Regulations 2013. The rule numbers on this page are the current ones.
• Response deadline: 28 days from the date the tribunal sent you the ET1 claim form (rule 17(1)) — not the date you received it, and not 28 working days.
• Response form: the ET3, which must include your full name, your address, and a statement of whether you resist any part of the claim, or the tribunal must reject it under rule 18.
• Extension of time: apply in writing under rule 21 before the deadline where possible, setting out your reasons; once the deadline has passed, you must also attach a draft response or explain why you cannot.
• If you do not respond: under rule 22, the tribunal decides whether it can determine the claim (or part of it) on the material already available; if it can, it issues a judgment — often referred to informally as a default judgment.
• Rejected response: you can apply for reconsideration under rule 20 within 14 days of the rejection notice.
• Acas: under rule 92, the tribunal automatically sends Acas a copy of the claim and response so a conciliation officer can offer to help the parties settle.

What is the ET3 and why it matters

An Employment Tribunal claim is a formal complaint brought by a worker or former worker against an employer, typically covering matters such as unfair dismissal, discrimination, unpaid wages, redundancy disputes, or breaches of contract. When a claim is accepted, the tribunal sends the employer a copy of the claim form (ET1) together with a notice setting the deadline for a reply, and the employer replies using the ET3 response form.

The ET3 is your opportunity to set out your side of the story, confirm which parts of the claim you accept or dispute, and explain the factual and legal basis for your defence. It also lets you bring a contract-based counter-claim of your own (an "employer's contract claim") where that is appropriate.

Tribunals operate under the Employment Tribunal Procedure Rules 2024. A response that is late, incomplete, or missing key information can be rejected, which may leave the claim effectively uncontested. Preparing a considered response from the outset tends to save considerable time, cost, and stress later in the process.

The Employment Tribunal Procedure Rules 2024 replaced the 2013 Rules

If you have dealt with a tribunal claim before 2025, note that the whole procedural rulebook changed. The Employment Tribunal Procedure Rules 2024 (SI 2024/1155) came into force on 6 January 2025 and replaced the Employment Tribunals (Constitution and Rules of Procedure) Regulations 2013. The Tribunal Procedure Committee, which now sets these rules, kept the substance of the response process largely the same but renumbered every rule. The table below maps the provisions that matter most to a respondent.

| Subject | 2013 Rules | 2024 Rules (current) | |---|---|---| | Response deadline (28 days) | Rule 16 | Rule 17 | | Rejection of response — form/missing information | Rule 17 | Rule 18 | | Rejection of response — presented late | Rule 18 | Rule 19 | | Reconsideration of a rejected response | Rule 19 | Rule 20 | | Applying for an extension of time | Rule 20 | Rule 21 | | Effect of no response / case not contested | Rule 21 | Rule 22 | | Acas conciliation | Rule 93 | Rule 92 |

Always check that anything you read — including older articles or template letters — refers to the current rule numbers. A small amendment in force from 2 March 2026 affected how the tribunal handles a late reply to an employer's contract claim, but it did not change the response rules described on this page.

The 28-day deadline: how it is calculated

The tribunal must receive your ET3 within 28 days of the date it sent you the copy of the ET1 claim form, under rule 17(1). This is a common point of confusion: the clock starts when the tribunal posts or transmits the claim, not when it lands on your desk, and it is a calendar-day count, not a working-day count.

If the tribunal sends the claim form to a different address than the one on the claim (for example, because it has updated contact details for you), it can direct that the 28 days runs from the date it sent the copy to that address instead. If the 28th day falls on a weekend or bank holiday, the general time rule treats a response received by midnight on the next working day as in time.

Completing and submitting the ET3

1. Read the claim carefully and note the deadline. Check the date the tribunal sent the ET1 to you, as this starts the 28-day clock. Read the claimant's allegations in full, identify which parts you agree with and which you dispute, and gather any employment records, correspondence, and policies relevant to the issues raised.
2. Complete the ET3 on the prescribed form. Use the official ET3 response form, either online or on paper. Under rule 18, the tribunal must reject the response if it is not on the correct form, or if it is missing your full name, your address, or a clear statement of whether you resist any part of the claim — so make sure those basics are unambiguous.
3. Submit within 28 days and keep a copy. File your completed ET3 with the tribunal before the deadline expires, whether online, by post, or by email to the relevant tribunal office. Keep a dated copy for your own records and quote the case number in any future correspondence.
4. Address the claimant's early conciliation details. The form asks you to confirm whether the Acas early conciliation information the claimant gave is correct. If anything looks wrong, or you were never contacted by Acas at all, say so — this can occasionally affect whether the tribunal has jurisdiction to hear the claim.
5. Set out your grounds of resistance clearly. For each allegation, state whether you agree, disagree, or say the point is outside your knowledge, and explain your version of events with dates and facts. If you want to raise a contract-based counter-claim against the claimant, include it in the relevant section of the ET3.

If your response is rejected

The tribunal must reject a response for one of two reasons. Under rule 18, it must reject a response that is not made on the correct form, or that does not include your full name, your address, and a statement of whether you resist any part of the claim. Under rule 19, it must reject a response received after the 28-day deadline (or after any extension granted under rule 21) — although it must not do this while an extension application is still pending.

Either way, the tribunal sends you a notice of rejection explaining why, and how to respond. Under rule 20, you can apply for reconsideration within 14 days of the date the rejection notice was sent. The application must be in writing, explain why the rejection was wrong (or, for a rule 18 rejection, show that the missing information has now been provided), and state whether you want a hearing. If the tribunal is persuaded the defect has simply been fixed, your response is treated as presented on the date the correction was received, not the original date.

Applying for an extension of time

If you cannot realistically meet the 28-day deadline, rule 21 lets you apply in writing for more time. The application must:

• set out your reasons for needing an extension in full;
• if the 28-day deadline has already passed, be accompanied by a draft of your intended response, or an explanation of why that is not possible; and
• say whether you want the application decided at a hearing.

The claimant has 7 days from receiving a copy of your application to object in writing. An Employment Judge usually decides the application without a hearing. If the extension is refused, any prior rejection of your response stands. If it is granted, any judgment already issued against you under rule 22 must be set aside.

Example: Greenacre Ltd receives an ET1 alleging unfair dismissal. The tribunal's covering letter shows it sent the claim form on 3 August, so the ET3 is due by 31 August. Greenacre's HR manager is unexpectedly unwell for two weeks and realises on 28 August that a considered response cannot be ready in time. Greenacre applies in writing that day under rule 21, explaining the reason and noting a draft response will follow within a few days. Because the deadline has not yet passed at the point of applying, no draft is required with the application itself.

What happens if you do not respond in time

This is the situation employers most want to avoid. Under rule 22, if the tribunal has not received a response by the 28-day deadline (or any extension granted), if a rejected response has no pending reconsideration application, or if you have stated that no part of the claim is contested, the tribunal must decide whether it can properly determine the claim — or part of it — on the material already available to it.

If it decides it can, it issues a judgment. This is often referred to informally as a "default judgment", although the Rules do not use that exact phrase — the tribunal is deciding the case on the papers it has, which will usually mean the claimant's account goes unchallenged. If the tribunal decides it cannot yet determine the claim on the papers, it lists a hearing instead, but you will only be allowed to take part in that hearing to whatever extent the tribunal permits — which is often limited to matters like the amount of compensation, rather than whether the claim succeeds at all.

Example: Greenacre Ltd misses the 31 August deadline entirely and does not apply for an extension. The tribunal considers the claim under rule 22 and decides it can determine liability for unfair dismissal on the ET1 alone, since there is no dispute from Greenacre on the papers. It issues a judgment on liability and lists a short hearing to assess compensation, at which Greenacre may only address the amount, not whether the dismissal was fair. If Greenacre later applies for an extension and it is granted, that judgment must be set aside under rule 21(5).

Acas conciliation once a claim is filed

Under rule 92, once tribunal proceedings are under way the tribunal sends a copy of the claim form and any response to an Acas conciliation officer, and tells both parties that Acas's services are available to them. A conciliator may then contact both sides to explore whether the case can be resolved without a full hearing, acting as a neutral intermediary rather than taking either side.

This sits alongside the earlier, separate requirement that in most cases a claimant must already have contacted Acas and obtained an early conciliation certificate under section 18A of the Employment Tribunals Act 1996 before they could present the ET1 at all — so by the time you receive a claim, Acas has usually already been involved once. Engaging constructively with post-claim conciliation can resolve a dispute faster, more privately, and at lower cost than proceeding all the way to a hearing. If a settlement is reached, it is normally recorded as an Acas COT3 agreement.

This guide provides general information about defending an Employment Tribunal claim as an employer in England and Wales. It is not legal advice and is not a substitute for advice tailored to your specific circumstances. The law described was accurate as at August 2026 and reflects the Employment Tribunal Procedure Rules 2024 — always check GOV.UK and legislation.gov.uk for the most current position, since rules and forms can change.

Last reviewed: August 2026 by a non-practising solicitor · Next review due: August 2027 or on legislative change.