Constructive Dismissal Employment Tribunal Claim (2026 Guide)

When Do You Need to File a Constructive Dismissal Claim?

You need to file an ET1 claim form if you resigned from your employment because your employer committed a fundamental breach of your employment contract — and you want the Employment Tribunal to treat that resignation as a dismissal.

This applies in situations such as:

• Your employer made your working environment intolerable through bullying, harassment, or sustained pressure
• You were demoted, had pay reduced, or had your duties drastically changed without consent
• Your employer failed to deal with a grievance properly, leaving you exposed to ongoing harm
• You were excluded from communications, stripped of responsibilities, or marginalised without explanation
• Management behaviour destroyed your ability to trust the organisation

The key legal foundation is the implied term of mutual trust and confidence. Every employment contract contains this implied term by operation of law. When your employer acts in a way that is calculated or likely to destroy that trust — without reasonable and proper cause — they have committed a fundamental breach. Your resignation in response to that breach is what the law treats as a constructive dismissal.

You do not need to wait until things become unbearable. However, you must be careful: if you continue working for an extended period after the breach without protest, the Tribunal may find that you have affirmed the contract and waived your right to claim.

What a Constructive Dismissal Claim Involves

A constructive dismissal claim is a species of unfair dismissal. It is brought on form ET1 to the Employment Tribunal and proceeds in the same way as a standard unfair dismissal claim, with one critical difference: you must first establish that you were dismissed at all.

To succeed, you must prove three things:

1. Fundamental breach — your employer breached a term of your contract (express or implied) in a serious way. Most cases rely on the implied term of trust and confidence, though other breaches (such as failure to pay wages or unlawful unilateral variation of terms) can also form the basis of a claim.
2. Resignation in response to the breach — you must show that you resigned because of the breach, not for an unrelated reason. A clear resignation letter referring to the breach is powerful evidence.

3. No affirmation — you must not have accepted the breach by continuing to work without protest for an unreasonable period after becoming aware of it.

Once you establish dismissal, the burden shifts to the employer to show a potentially fair reason for the dismissal. In practice, employers in constructive dismissal cases often struggle at this stage, because the conduct that caused you to resign rarely maps onto a fair dismissal reason. The Tribunal then considers whether the employer acted reasonably in all the circumstances.

You must also have at least two years of continuous employment to bring an unfair constructive dismissal claim, unless the reason for dismissal falls within a list of automatically unfair reasons (such as whistleblowing or pregnancy-related dismissal), in which case there is no qualifying period.

How to Complete Your ET1 for Constructive Dismissal: Step by Step

The ET1 is the claim form you submit to the Employment Tribunal to start your case. You file it online via the GOV.UK Employment Tribunal service. This section walks you through the key sections as they apply to a constructive dismissal claim.

Before you begin: Early Conciliation

Before you can file an ET1, you must contact ACAS and go through Early Conciliation. This is mandatory. ACAS will contact your employer and attempt to reach a settlement. If conciliation fails or either party declines, ACAS issues you an Early Conciliation Certificate with a unique reference number. You need this number to submit your ET1. Keep the certificate safe — it is also important for calculating your filing deadline.

Section 2 — Respondent Details

Enter your employer’s full legal name and address. If your employer is a limited company, use the registered company name exactly as it appears on Companies House. Getting the respondent name wrong can complicate service of proceedings.

Section 5 — Employment Details

State your start date, the date your employment ended (the date of your resignation), and confirm that you resigned. Do not leave this ambiguous. The Tribunal needs to understand from the outset that this is a constructive dismissal case.

Section 6 — Earnings and Benefits

Complete all boxes accurately. Your potential compensation is based on your weekly gross and net pay. Include all contractual benefits: pension contributions, car allowance, private medical insurance. Underreporting here can reduce your eventual award.

Section 8 — Type of Claim

Tick “Unfair dismissal” as your primary claim. You may also have additional claims arising from the same facts — for example, a claim for unpaid notice pay (breach of contract), unlawful deduction of wages, or discrimination. Identify all claims at this stage; you cannot easily add claims later.

Section 8.1 — Details of Claim (the narrative)

This is the most important part of your ET1. Write clearly and chronologically. The Tribunal does not want a diary of grievances — it wants to understand the breach and your response to it. Structure your narrative as follows:

• The breach: Describe the specific conduct that constituted the fundamental breach. Be precise about dates, what was said or done, and who was involved. If the breach was a course of conduct rather than a single incident, describe the pattern.
• The implied term: Explain how the conduct breached the implied term of mutual trust and confidence (or whichever other term is relevant). You do not need legal jargon — plain English is preferred.
• Your response: Describe how you raised the matter with your employer (grievance, informal complaint, written correspondence) and what, if any, response you received.
• The resignation: State clearly that you resigned in direct response to the breach. If you wrote a resignation letter citing the breach, refer to it. Give the exact date.
• Loss: Briefly indicate the financial loss you have suffered: loss of earnings from the date of resignation, loss of benefits, and any future loss you anticipate.

Keep the narrative focused. Two to three concise paragraphs, clearly structured, will serve you better than a lengthy account that buries the key legal points.

Supporting Documents

You do not attach documents to the ET1 itself. However, you should gather your evidence immediately: resignation letter, correspondence with your employer, emails, grievance documentation, payslips, and your employment contract. These will be disclosed later in the proceedings.

Submitting the form

Review every section before you submit. Once filed, the ET1 is served on your employer and becomes part of the formal record. You will receive a claim number by email.

Key Deadlines for Constructive Dismissal Claims

The deadline for filing a constructive dismissal ET1 is three months minus one day from the effective date of termination — that is, the date your resignation took effect.

If your notice period was worked, the effective date of termination is the last day of your notice period. If you resigned with immediate effect (which is permissible where the breach is sufficiently serious), the effective date is the day you resigned.

Early Conciliation affects the deadline. The period during which ACAS is conducting Early Conciliation is paused (tolled) from your limitation period. Your ACAS certificate will show the dates. When you calculate your filing deadline, you must add the conciliation period to your original three-month window. Do not rely on a rough calculation — use the exact dates on your certificate.

The Tribunal has a limited discretion to accept a claim filed out of time if it was not reasonably practicable to file in time. This is a narrow test. Do not assume you will benefit from it. File on time.

What Happens After You File?

Once you submit your ET1:

1. The Tribunal sends a copy to your employer (the respondent), who has 28 days to submit a response on form ET3.
2. The Tribunal may hold a Preliminary Hearing to consider jurisdiction issues (for example, whether you have two years’ service) or to give case management directions.
3. At a Case Management Hearing, the Tribunal sets a timetable for the exchange of witness statements, disclosure of documents, and the date of the final hearing.
4. Disclosure takes place: both parties exchange relevant documents.
5. Witness statements are prepared and exchanged before the hearing.
6. The Final Hearing takes place before an Employment Judge (and, in complex cases, two lay members). Each party presents their case, witnesses are cross-examined, and the Tribunal deliberates.
7. If you succeed, the Tribunal issues a Judgment and moves to a Remedy Hearing to determine compensation.

Most Employment Tribunal cases settle before final hearing. Even after the ET1 is filed, ACAS and direct negotiations remain possible.

Common Mistakes in Constructive Dismissal Claims

1. Resigning without first raising a grievance

The Tribunal will ask what you did to address the situation before resigning. Resigning without raising a formal grievance — or without at least documenting your concerns in writing — makes your case significantly harder. It also gives your employer ammunition to argue you did not give them an opportunity to remedy the breach.

2. Delaying the resignation after the breach

If you discovered the fundamental breach and continued working for weeks or months without protest, the Tribunal may find you affirmed the contract. Affirmation extinguishes your right to treat the contract as repudiated. Once you decide the breach is serious enough to resign over, act promptly.

3. Writing a vague or conciliatory resignation letter

A resignation letter that cites “personal reasons” or expresses regret undermines the connection between the breach and your resignation. Your letter should clearly and calmly state that you are resigning in response to the employer’s fundamental breach of contract, specifying the conduct.

4. Missing the Early Conciliation step

Attempting to file an ET1 without a valid ACAS Early Conciliation Certificate will result in the claim being rejected. Contact ACAS before you do anything else.

5. Misidentifying the breach

Not every act of poor management constitutes a fundamental breach. Ordinary workplace stress, a single unkind comment, or a minor procedural failing is unlikely to satisfy the threshold. You must be able to identify conduct that is sufficiently serious — or a course of conduct that cumulatively crosses the threshold — to justify treating the contract as repudiated.

6. Understating financial loss

Compensation in unfair dismissal cases is subject to a basic award (calculated by reference to age, length of service, and weekly pay) and a compensatory award (capped at the lower of one year’s gross pay or the statutory cap, which is reviewed annually). Many claimants underestimate their compensatory loss by failing to account for pension loss, benefit loss, or the time it realistically takes to find equivalent employment.

Do I need to have raised a grievance before I can claim constructive dismissal?

A: There is no strict legal requirement to raise a formal grievance before resigning, but the Tribunal will scrutinise what steps you took to address the situation before leaving. Failing to raise a grievance can lead to a Polkey reduction in compensation or an uplift in favour of the employer. In practice, if you have time to do so safely, raising a grievance before you resign — or at minimum putting your concerns in writing — substantially strengthens your position.

Q: I resigned with immediate effect. Does that affect my claim?

A: No, provided the breach was sufficiently serious. Where an employer has committed a serious fundamental breach — particularly of the implied term of trust and confidence — you are entitled to treat the contract as repudiated and leave immediately. You should make clear in your resignation letter that you are leaving without notice by reason of the employer’s repudiatory breach, and that you accept that breach as ending the contract.

Q: Can I claim constructive dismissal if I have less than two years’ service?

A: For a standard unfair constructive dismissal claim, you need at least two years of continuous employment. However, if the reason you were driven out relates to a protected characteristic (such as race, sex, disability, religion, or sexual orientation), a protected disclosure (whistleblowing), or another automatically unfair reason, there is no qualifying period. If you believe your situation falls into one of these categories, identify the relevant claim on your ET1 alongside the unfair dismissal claim.

Q: How much compensation could I receive if I win?

A: Compensation comprises a basic award (calculated in the same way as a statutory redundancy payment, based on age, length of service, and weekly gross pay up to the statutory cap) and a compensatory award for financial loss actually suffered. The compensatory award is subject to a statutory cap — currently the lower of 52 weeks’ gross pay or the annual cap (reviewed each April). Additional awards are available where an employer has failed to comply with a reinstatement or re-engagement order, and separate injury to feelings awards are available where a discrimination claim succeeds alongside the constructive dismissal claim.

Q: What if my employer offers me money to settle before the hearing?

A: Settlement is common in Employment Tribunal cases and can be reached at any stage. Any settlement reached through ACAS is formalised via a COT3 agreement. A settlement reached without ACAS involvement must be recorded in a Settlement Agreement (formerly a Compromise Agreement), which requires you to have received independent legal advice before signing. You are never obliged to accept a settlement offer, and you should consider the strength of your case and the risks of litigation carefully before deciding. Chris can help you understand what your claim is worth before you make any decision.

Related Court Forms & Guides

• Form N260: Statement of Costs — the costs schedule used at summary assessment.
• Form N244: Application Notice — the form for interim applications.
• Start a Money Claim Online (OCMC) — where most civil money claims begin.
• Particulars of Claim — setting out the basis of your claim.
• Civil Court Forms Index — every civil court form guide in one place.

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Frequently asked questions

What is a constructive dismissal claim?

It is a species of unfair dismissal, brought on form ET1 to the Employment Tribunal. You were not formally dismissed — you resigned — but the law can treat your resignation as a dismissal where your employer committed a fundamental breach of your employment contract and you resigned in response to it. The key foundation in most cases is the implied term of mutual trust and confidence, which every employment contract contains by operation of law.

What do I have to prove to succeed?

Three things, as the guide above sets out: a fundamental breach by your employer (express or implied, most often the implied term of trust and confidence); that you resigned in response to that breach and not for an unrelated reason; and that you did not affirm the contract by continuing to work without protest for an unreasonable period after becoming aware of the breach. Once dismissal is established, the burden shifts to the employer to show a potentially fair reason.

Do I have to contact ACAS before filing my ET1?

Yes. Early Conciliation through ACAS is mandatory before you can file an ET1. ACAS will contact your employer to try to reach a settlement; if it fails or either party declines, ACAS issues an Early Conciliation Certificate with a unique reference number that you need to submit your ET1. Keep the certificate safe — it also matters for calculating your deadline.

What is the deadline for a constructive dismissal ET1?

The guide states the deadline is three months minus one day from the effective date of termination — the date your resignation took effect. Early Conciliation pauses (tolls) that period, so you must add the conciliation period shown on your ACAS certificate. Use the exact dates rather than a rough calculation, and file on time: the Tribunal’s discretion to accept a late claim is narrow. Always check the current position for your situation.

Do I need a minimum length of service?

The guide explains you must generally have at least two years of continuous employment to bring an unfair constructive dismissal claim — unless the reason falls within a list of automatically unfair reasons (such as whistleblowing or pregnancy-related dismissal), in which case there is no qualifying period.

What happens after I file the ET1?

The Tribunal sends a copy to your employer, who has 28 days to respond on form ET3. There may be a Preliminary or Case Management Hearing to deal with jurisdiction and set a timetable, followed by disclosure of documents, exchange of witness statements, and a Final Hearing before an Employment Judge. If you succeed, the Tribunal moves to a Remedy Hearing on compensation. Most cases settle before the final hearing.

Related guides: ET1 Employment Tribunal claim guide · ET3 employer response guide · Writing a witness statement · All civil court forms