A significant update to UK employment law is coming. From 1 December 2025, the Acas Early Conciliation period will be temporarily extended from six weeks to twelve weeks.
This change, introduced by The Employment Tribunals (Early Conciliation: Exemptions and Rules of Procedure) (Amendment) Regulations 2025, gives individuals and employers more time to settle disputes without a formal tribunal hearing.
But what does this mean for your Employment Tribunal deadline? This guide explains the new Acas conciliation rules, how they impact your ET1 submission timeline, and the practical steps you need to take.
What is Acas Early Conciliation?
Acas Early Conciliation is a mandatory step that anyone wishing to make an Employment Tribunal claim must go through first. It’s a free and confidential service where a trained Acas conciliator helps you and your employer discuss the issue and explore a settlement.
- If an agreement is reached, it is formalised in a legally binding COT3 agreement.
- If no agreement is found, Acas issues an Early Conciliation Certificate. This certificate contains a number you must include on your ET1 claim form to proceed with your tribunal case.
Until now, this process lasted a maximum of six weeks. From December 2025, it will be 12 weeks.
What’s Changed with the 2025 Acas Extension?
The core change is simple: the timeframe for Early Conciliation has doubled.
- New Rule: A 12-week maximum conciliation period.
- Effective Date: 1 December 2025.
- Who It Affects: Anyone who starts Early Conciliation with Acas on or after this date. If you start the process before 1 December 2025, the old six-week rule will still apply to your case.
This extension provides a longer, potentially more meaningful opportunity to resolve a dispute like unfair dismissal or discrimination without the stress and cost of a tribunal.
How the 12-Week Rule Affects Your ET1 Tribunal Deadline
This is the most critical part to understand. While you have more time for conciliation, your overall tribunal time limits still apply—they are just paused.
Here’s a breakdown of how it works:
- The "Stop the Clock" Rule: When you start Early Conciliation, the clock on your primary tribunal deadline is paused.
- The New 12-Week Pause: This "pause" can now last for up to 12 weeks while the conciliation takes place.
- The Clock Restarts: Once Acas issues your Early Conciliation Certificate, the clock restarts. You will always have at least one calendar month from the certificate date to submit your ET1 form to the Employment Tribunal.
Practical Example:
- Let’s say you were unfairly dismissed on 1 May 2026. Your primary deadline to contact Acas is 31 July 2026 (3 months minus one day).
- You contact Acas and start Early Conciliation on 5 December 2026. The conciliation process lasts for 10 weeks.
- Your original tribunal deadline is extended by those 10 weeks. Once you receive your certificate, you will have at least one month to file your ET1, but your new final deadline will be your original deadline + 10 weeks.
Crucial Point: Missing your final ET1 submission deadline after the certificate is issued can lead to your claim being rejected by the tribunal. The extended conciliation period makes careful deadline tracking more important than ever.
Next Steps: How to Prepare for the New Rules
If you are considering or are already in the Early Conciliation process, here’s what you should do.
- Check Your Acas Start Date: The 12-week rule only applies to cases started on or after 1 December 2025. Confirm your date to know which rules apply to you.
- Use the Extra Time Wisely: Don't wait. Use the additional weeks to:
- Gather evidence (emails, letters, performance reviews).
- Prepare a detailed timeline of events.
- Draft your ET1 form and Particulars of Claim so they are ready to submit.
- Track Your Deadlines Meticulously: Note the date your Early Conciliation Certificate is issued. Calculate your new, final submission deadline from that date. Setting reminders is essential.
- Seek Expert Guidance: Navigating tribunal deadlines and procedures can be complex. Valla offers tools, templates, and guides to help you manage your claim confidently and ensure you meet all critical deadlines.
Key Takeaways
- The Acas conciliation period is extended from 6 to 12 weeks for cases started on or after 1 December 2025.
- This provides more time to settle a dispute but extends your overall tribunal timeline.
- Your ET1 submission deadline is paused during conciliation and resumes once the certificate is issued.
- Use the extra time to prepare your case thoroughly, but be vigilant in tracking your final deadline to avoid your claim being struck out.
Source: Valla