Early Conciliation Is Now 12 Weeks — Check Your Deadline Again

There is a change to employment tribunal deadlines that came in on 1 December 2025 and it is still catching people out — including, in our experience, people who assume they are out of time when they are not.

The ACAS Early Conciliation period doubled. It used to run for a maximum of six weeks. It now runs for a maximum of twelve. Because Early Conciliation pauses the clock on your tribunal deadline, that change can push your last possible claim date months later than you would expect.

If you have been told you have missed your deadline, it is worth checking again.

What Early Conciliation is

Before you can bring most employment tribunal claims, you have to notify ACAS first. This is not optional — it is a mandatory step, with a small number of exemptions. ACAS then offers to help you and your employer reach a settlement without going to tribunal.

Taking part in the settlement discussions themselves is optional. You can tell ACAS you don't want them to contact your employer, and the process ends immediately. But you still have to notify them, because you need the certificate they issue at the end in order to submit your ET1 claim form.

The service is free and confidential.

What changed on 1 December 2025

Under the Employment Tribunals (Early Conciliation: Exemptions and Rules of Procedure) (Amendment) Regulations 2025, the maximum Early Conciliation period went from six weeks to twelve.

The reason is capacity. Tribunal backlogs have grown sharply — there were around 45,000 live single claims at the end of March 2025, up from roughly 33,000 the year before. There has also been a real problem where claimants waited weeks just for a conciliator to be assigned, leaving almost no time to conciliate inside a six-week window.

The change applies to notifications made on or after 1 December 2025. If you started Early Conciliation before that date, the old six-week maximum still applies to your case.

Why this affects your deadline

This is the part that matters most, and it is the part people get wrong.

Most tribunal claims have a primary time limit of three months less one day from the event you are complaining about — usually your dismissal, or the act of discrimination. You must contact ACAS within that period.

When you notify ACAS, the clock stops. It does not run again until Early Conciliation ends and ACAS issues your certificate. So the conciliation period effectively gets added on to your deadline.

With a six-week maximum, that bought you up to six extra weeks. With a twelve-week maximum, it can buy you up to twelve. On top of that, you always have at least one month from the date on your Early Conciliation certificate to submit your ET1, even if your original three-month deadline has passed in the meantime.

Put together, a claim about something that happened five or six months ago may still be perfectly in time. That surprises people, and it is why the "I've left it too late" assumption is so often wrong.

A worked example

Say you were dismissed on 1 March. Your primary deadline — three months less one day — is 31 May. You contact ACAS on 20 May, comfortably inside it.

Early Conciliation then runs. If it goes the full twelve weeks and your certificate is issued on 12 August, the clock that was paused on 20 May restarts. You had 11 days left of your original period, but the one-month minimum applies instead because it is more generous. You would have until around 12 September to submit your ET1.

Under the old six-week rule, the same dismissal would have produced a deadline in early July. The change is not small.

What this does not change

Be careful here, because the extension is easy to over-read:

• You must still contact ACAS within the primary time limit. The extension helps you after you notify, not before. Miss the three-months-less-one-day window to notify, and the twelve weeks does nothing for you.
• Twelve weeks is a maximum, not a fixed period. If either side says they are not interested, ACAS can issue the certificate immediately and the clock restarts straight away.
• Not every claim has a three-month limit. Statutory redundancy pay claims and equal pay claims work to six months. Some claims have their own rules. Never assume the standard limit applies to yours.
• Tribunals can extend time, but rarely. Don't rely on it.

If you think you might be out of time

Contact ACAS anyway. There is no penalty for notifying, and the certificate is free. A conciliator can tell you where you stand, and if you are inside the limit after all, you have preserved your position by notifying.

The worst outcome is deciding for yourself that you are too late, doing nothing, and finding out afterwards that you had weeks in hand.

Should you actually conciliate?

Worth thinking about properly rather than treating it as a box to tick. Tribunal cases now routinely take a year or more to reach a hearing, and that is a long time to hold your life still. Settlement through ACAS is free, faster, confidential, and a settlement reached through a conciliator is legally binding.

It is not the right answer for everyone. Some cases need a tribunal, and some employers will not move. But the extra six weeks does give a real opportunity to test whether a settlement is possible before committing to litigation, and that opportunity did not meaningfully exist when conciliators were being assigned five weeks into a six-week window.

The short version

Early Conciliation now lasts up to twelve weeks instead of six, for notifications made on or after 1 December 2025. Your tribunal clock is paused for that whole period, and you get at least a month from your certificate date to file. You must still contact ACAS within three months less one day of what happened. If you have written off a claim as out of time, check the arithmetic again.