UK Workplace Issue Playbook · 2026
How do I file an employment tribunal claim in the UK?
Why this matters
Many employees who could win don't claim because they don't know the procedure or assume it's expensive. UK tribunals are free (no fees since 2017), accessible, and procedurally fair. The biggest failure mode is missing the time limit (3 months less 1 day from the act complained of) — once missed, almost no extensions are granted.
Legal basis
Employment Tribunals Act 1996; Employment Tribunals (Constitution & Rules of Procedure) Regulations 2013; ACAS Code; mandatory conciliation under Trade Union & Labour Relations (Consolidation) Act 1992 s.18A.
Step-by-step playbook
1) Confirm time limit: 3 months less 1 day from the act complained of (dismissal date, last act of discrimination, etc.). Equal pay has a 6-month limit. 2) File ACAS Early Conciliation online (free): www.acas.org.uk/early-conciliation. ACAS contacts both parties and tries to settle. 3) Conciliation period: up to 6 weeks (can be extended). 4) ACAS issues a certificate at the end. The time limit is paused during conciliation. 5) After certificate, file ET1 form online: www.gov.uk/make-claim-employment-tribunal. 6) Within 1 month plus the ACAS extension. 7) Employer files ET3 response within 28 days. 8) Tribunal manages case with directions hearing, disclosure, witness statements. 9) Final hearing: half-day to several weeks depending on complexity. 10) Decision in writing usually within 6 weeks of hearing.
Letter / template
ET1 grounds of claim outline (the 'particulars' attached to ET1): 'Claimant: [Your name] Respondent: [Employer name] Claim: Unfair dismissal under Employment Rights Act 1996 ss.94-98 [add other claims as applicable] **Background** 1. The Claimant was employed by the Respondent from [date] to [date] as [role]. 2. The Claimant's gross salary at termination was £[X] per year. **Facts** 3. On [date], [event]. 4. On [date], [event]. [continue chronologically] **The Dismissal** [N]. On [date], the Claimant was dismissed [summarily / on notice]. The reason given was [reason]. **Grounds** [N+1]. The dismissal was procedurally unfair because: (a) [no investigation] (b) [no fair hearing] (c) [denied right to appeal] [N+2]. The dismissal was substantively unfair because: (a) [the reason was not within the range of reasonable responses] (b) [the Claimant's conduct did not warrant dismissal] [N+3]. [If automatic unfair: This was an automatically unfair dismissal under [s.103A whistleblowing / s.99 pregnancy / etc.]] **Loss** [N+4]. The Claimant has suffered loss including: (a) Notice pay: £[X] (b) Compensatory: £[Y] (calculated as [N] months at £[rate]) (c) Pension loss: £[Z] (d) [Other] **Remedies sought** [N+5]. The Claimant seeks: compensation; recommendations under EqA s.124 (if applicable); a declaration. Date: Signed: [Claimant or representative]'
What NOT to do
Don't: miss the 3-month time limit; skip ACAS conciliation (tribunal will reject the claim); file ET1 with vague allegations (the 'particulars' must be specific); fail to attend tribunal hearings; ignore tribunal directions; rely on unprepared witnesses; underestimate the complexity (professional representation often pays for itself); decline reasonable settlement offers without taking advice.
Worked example
Mark filed an ET1 for unfair dismissal after his ACAS conciliation didn't settle. He drafted detailed particulars listing 14 specific procedural and substantive failures. The employer's ET3 was vague. At the directions hearing, the judge ordered specific disclosure that the employer struggled to provide. The case settled 3 weeks before final hearing for £35,000 + agreed reference. Detailed particulars created the leverage; unspecific claims would have been weaker.
Recruiter pro tip
The single most important document in UK tribunal claims is the 'particulars of claim' attached to your ET1. Vague particulars produce vague defences and weak negotiating leverage; detailed particulars (with dates, witnesses, document references) produce specific defences and strong settlement leverage. Spend 5+ hours drafting them carefully, ideally with a specialist solicitor. Most cases settle on the strength of the particulars alone — they signal you've done the work and will follow through.
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