To file an ET1 claim form with an employment tribunal, you must first complete ACAS early conciliation and obtain a certificate number, then submit the completed form within three months minus one day of the event you are complaining about. Filing is free, but the tribunal rejects incomplete claims outright, and a missed deadline almost always ends the case before it starts. The requirements for the ET1 claim form fall into three parts: the prerequisite step with ACAS, the information the form itself demands, and getting the submission through the door on time.
Start With ACAS Early Conciliation
You cannot file an ET1 until you have notified the Advisory, Conciliation and Arbitration Service that you intend to bring a claim.1Acas. Early Conciliation ACAS then offers early conciliation, in which a neutral conciliator tries to settle the dispute without a tribunal hearing. The process can last up to 12 weeks.2Acas. How the Process Works – Early Conciliation
If it does not resolve things, ACAS issues an Early Conciliation Certificate with a unique reference number. You need that number on the ET1. The tribunal rules require the claim to contain either an early conciliation number, confirmation that the claim does not institute relevant proceedings, or confirmation that an exemption applies.3Legislation.gov.uk. The Employment Tribunal Procedure Rules 2024 – Rule 12 Without one of these, the claim is rejected.2Acas. How the Process Works – Early Conciliation
If you are claiming against more than one employer or organisation, notify ACAS separately for each respondent. The certificate itself can list multiple respondents, but the initial notifications must be made individually. A small number of claim types are exempt from early conciliation. ACAS cannot tell you whether yours qualifies, but if you believe it does, you indicate the exemption on the form instead of a certificate number.
The Filing Deadline
Most employment tribunal claims must be filed within three months minus one day of the date the problem happened.4Acas. Employment Tribunal Time Limits For unfair dismissal, the clock runs from your effective date of termination. For discrimination, from the date of the discriminatory act. More claims are lost on timing than on merit.
How Early Conciliation Extends the Clock
If you notify ACAS within the original time limit, the countdown pauses until conciliation ends.5Acas. Employment Tribunal Time Limits – Section: How Early Conciliation Can Pause Your Time Limit Once you receive your certificate, you have at least one month from that date to file the ET1.2Acas. How the Process Works – Early Conciliation Sometimes longer. Working out the exact deadline after conciliation gets complicated fast, so treat the one-month minimum as your hard stop and file well before it runs out.
If You Miss It
For unfair dismissal and most statutory claims, the tribunal can extend the deadline only where it was “not reasonably practicable” to file on time. That is an extremely high bar. Stress alone is not enough. Unless you were physically incapacitated or genuinely prevented from filing, the deadline stands. Discrimination claims under the Equality Act 2010 use a more flexible “just and equitable” test, giving the tribunal broader discretion, but an extension is still far from guaranteed. Neither test is something to plan around.
What the Form Asks For
You can get the ET1 from the GOV.UK website, either as an online form or a downloadable PDF.6GOV.UK. Make a Claim to an Employment Tribunal – Form ET1 Incomplete or inaccurate entries are one of the main reasons claims are rejected or delayed.
Your Details and the Respondent’s Legal Name
You need your full name, address, and contact information. For the respondent, provide the employer’s correct legal name and address. This one catches people out. If your employer trades under one name but is registered as a different company, use the registered company name, which appears on your employment contract, offer letter, or payslips.7GOV.UK. Make a Claim to an Employment Tribunal Getting the respondent’s name wrong is a ground for rejection under the tribunal rules, and fixing it after the deadline can be difficult or impossible.3Legislation.gov.uk. The Employment Tribunal Procedure Rules 2024 – Rule 12
Employment Dates and Pay
The form asks for your employment start date, end date if applicable, job title, gross weekly pay before tax, and net weekly pay after deductions. These figures are not just administrative; they feed directly into any compensation calculation later. Pull them from your payslips, employment contract, or P45. Inaccurate pay figures complicate the compensation calculation and can undermine your credibility with the judge.
Pension Information
If you had a workplace pension, gather your employer’s contribution rate. The tribunal can award compensation for lost pension rights, and the calculation depends on whether you were in a defined contribution scheme, where the employer’s contribution percentage matters most, or a defined benefit scheme, where projected retirement income and accrual rates matter. If you have already started a new job with pension benefits, the difference between the old and new scheme feeds into the loss calculation. Getting the information from your pension administrator early saves time if the case reaches a hearing.
Writing the Statement of Claim
The details-of-claim section is where you set out what happened and why you say it was unlawful. It is the foundation of the whole case. A vague or disorganised statement makes it easier for the respondent to argue there is no real case to answer, and harder for the judge to understand what is actually being alleged.
Write in chronological order. Give specific dates, specific events, and the names of the people involved. Avoid general complaints that your employer was “unfair” or “unreasonable” without tying them to concrete actions. If you were dismissed, describe the process your employer followed and where it went wrong. If you experienced discrimination, identify the protected characteristic involved and describe how you were treated differently or unfavourably.8Legislation.gov.uk. Equality Act 2010 – Section 4 – Protected Characteristics
You do not need to cite statutes, but naming the type of claim helps the tribunal route the case correctly. For a whistleblowing claim, trace the timeline from the disclosure you made to the treatment that followed, including any change in your employer’s attitude after you raised concerns. For constructive dismissal, explain the conduct that made it impossible for you to keep working and why you felt compelled to resign.
Separate different complaints into distinct paragraphs. If you have both a discrimination claim and an unfair dismissal claim arising from the same facts, lay them out as separate threads. That structure lets the respondent see exactly what to answer and lets the judge assess the claim without a preliminary hearing just to work out what it is about.
Choosing a Remedy
The form asks what outcome you want if the claim succeeds. The options are compensation, reinstatement to your old job, or re-engagement in a different role with the same employer. Most claimants tick compensation only, and tribunals rarely order reinstatement or re-engagement in practice because the employment relationship has usually broken down beyond repair. If you genuinely want your job back, asking for reinstatement can still be tactically useful: if the employer refuses, the tribunal can increase your compensation.
You do not need a precise figure at this stage. “Compensation to be assessed” or simply “damages” is standard and leaves the detailed calculation for later.
How to Submit
You can file online through the tribunal’s digital portal or by posting a paper form to the relevant tribunal office.7GOV.UK. Make a Claim to an Employment Tribunal Online is faster and gives you an instant acknowledgment of receipt, which is valuable proof that you filed on time. A postal filing counts as received when it arrives at the tribunal office, not when you post it, so build in time for delivery.
A claim is only considered “presented” when it reaches the tribunal in the prescribed manner.9Legislation.gov.uk. The Employment Tribunals (Constitution and Rules of Procedure) Regulations 2013 – Schedule 1 If you file by post and the form arrives a day late, your only argument is that it was not reasonably practicable to file earlier. That is not a fight worth walking into. File online unless you have no alternative.
If several people share the same complaint against the same employer, a lead claimant files an ET1 and additional claimants use Form ET1A to join it.10GOV.UK. Make a Claim With Others to an Employment Tribunal – Form ET1A Each claimant still needs their own ACAS early conciliation certificate.
After the Tribunal Receives Your Claim
Staff review the form for completeness. If anything is missing, the tribunal rejects the claim and sends a notice explaining why and how to apply for reconsideration.3Legislation.gov.uk. The Employment Tribunal Procedure Rules 2024 – Rule 12 The most common rejection grounds are a missing early conciliation number, an incomplete respondent name or address, and a form that is not in the prescribed format.
If the form is accepted, the tribunal sends a copy of the claim to the respondent along with an ET3 response form. The respondent has 28 days from the date the tribunal sent the claim to return it.11GOV.UK. Employment Tribunal – What Happens After You Submit a Claim (T421) Once both sides have filed, the tribunal issues case management directions covering evidence, witness statements, and a hearing date.
Amending a Filed Claim
If you spot an error or a missing allegation after filing, you can apply to amend the ET1. The tribunal weighs the potential unfairness to each side in deciding whether to allow the change. Minor corrections, like fixing a date or clarifying existing facts, are usually granted. Adding an entirely new type of claim, especially one already out of time, is much harder to get past a judge. The earlier you spot the issue and apply, the better your chances.
Filing Is Free, But There Is Still Financial Risk
There is no fee to submit an ET1, but that is not the same as no financial risk. A tribunal can order you to pay the respondent’s costs if it finds that you, or your representative, acted unreasonably, vexatiously, or disruptively in bringing or conducting the proceedings. Without a detailed assessment the maximum is £20,000; with a detailed assessment there is no cap.12Legislation.gov.uk. The Employment Tribunal Procedure Rules 2024 – Rule 76 Costs orders remain the exception rather than the rule, and the threshold is higher than in ordinary civil courts. But pursuing a claim you know has no merit, refusing reasonable settlement offers, or causing unnecessary delays can all trigger one. The tribunal can take your ability to pay into account, but is not obliged to.
If the tribunal considers that a specific part of your claim has little reasonable prospect of success, it can also order you to pay a deposit of up to £1,000 as a condition of continuing with that part. Ability to pay must be considered when setting the amount. If you do not pay the deposit by the deadline, that part of the claim is struck out.