Can I dismiss someone during their probation period?

31st August 2026

Usually yes. But if you are asking this question in late 2026, the honest answer has changed shape, and the thing that decides your risk is no longer how long someone has worked for you. It is the date the dismissal actually takes effect.

Here is what that means in practice, and what you should do about it this week.

Where the law stands today

Until the end of this year, an employee needs two years of continuous employment to bring an ordinary unfair dismissal claim. That comes from section 108 of the Employment Rights Act 1996. Someone six weeks into a job cannot bring one, and neither can someone six months in.

So if you are letting a probationer go this week, an ordinary unfair dismissal claim is not your exposure. That is genuinely reassuring, and a lot of managers spend weeks agonising over a decision that carries very little of the risk they imagine.

It is not free of risk, though, and the risks that remain do not care about length of service.

The things that apply from the first day

Three categories bite regardless of how long someone has been with you.

Discrimination. Protection under the Equality Act applies from day one, and to job applicants before that. Acas confirms this on its probation page. If the reason you are ending probation is connected to disability, pregnancy, race, age, religion or any other protected characteristic, the short service does not help you at all. Compensation in discrimination claims is uncapped.

Automatically unfair reasons. No qualifying period applies to these either. Acas lists them: whistleblowing, raising health and safety concerns, pregnancy or family leave, jury service, trade union membership, asking for a legal right such as the minimum wage, making a flexible working request. If your probationer raised any of those in the weeks before you decided, you have a problem that their start date will not solve.

Notice. Once someone has been employed for a month, section 86 entitles them to at least a week’s notice, or whatever their contract says if it is longer. Getting this wrong is a breach of contract claim, small but avoidable.

What changes on 1st January 2027

From that date the qualifying period for unfair dismissal drops from two years to six months. Acas has the confirmed timeline, and the commencement date is fixed in the Employment Rights Act 2025 (Commencement No. 4 and Transitional and Saving Provisions) Regulations 2026. We have written separately on what else lands on that date, including the removal of the cap on the compensatory award.

Two pieces of stale advice are still circulating, so ignore them if you see them. There is no statutory probation period of nine months with a lighter dismissal process. That idea was in earlier versions of the reforms and was dropped in the government’s announcement of 27th November 2025, which replaced it with a straight qualifying period of six months (analysis from the law firm Lewis Silkin). There is no softer procedure waiting for you at month seven. Full unfair dismissal rights simply switch on.

The trap, and it is a real one

This is the part most published guidance skips, and it is the reason a lot of employers are going to get caught.

The new qualifying period is triggered by the effective date of termination, not by when the employee started. Regulation 4 of those commencement regulations turns on whether the effective date of termination falls before or after 1st January 2027. The clearest plain English summary we found is from the law firm Forbes Solicitors.

So this is not a rule about new hires. Consider someone who started on 1st June 2026. On 20th December 2026 you can dismiss them, and they have no ordinary unfair dismissal claim. On 5th January 2027 the same person, the same performance concerns, the same conversation, now has more than six months of service and a claim you would have to defend.

It gets tighter. If you dismiss on 29th December 2026 and pay a week in lieu of notice, your instinct is that the employment ended in 2026. For the purposes of the qualifying period it did not. Section 97(2) treats the effective date of termination as the date statutory notice would have expired, which pushes it into January. You have landed inside the new regime without meaning to.

Does a longer probation protect you?

No, and this is the most expensive misunderstanding in small business HR.

Probation is a contractual idea. You can make it three months, six months or twelve. It has no bearing whatsoever on the statutory clock. A twelve month probation does not delay anyone’s unfair dismissal rights past 1st January 2027. It just gives you a longer period in which you feel you have time and do not actually have it.

If your probation runs to six months, the contractual review and the statutory cliff arrive at almost exactly the same moment. That is not a coincidence you can rely on. Diarise the earlier of the two.

So should you rush decisions before January?

Take the deadline seriously, but do not let it push you into a dismissal you were not otherwise going to make. Two reasons.

First, a decision that is obviously timed to beat a change in the law reads badly in front of a tribunal, and it does nothing about the day one claims that are your real exposure. Second, the process that makes a probation dismissal defensible is short. It is one meeting where you tell them the concern in advance, show them the evidence, let them respond, and then decide. Gov.uk sets out the expected steps, including the right to be accompanied and the right to appeal.

Worth knowing: the Acas Code of Practice covers poor performance as well as misconduct, and a tribunal can increase an award by up to 25 per cent where an employer unreasonably fails to follow it. That uplift applies to discrimination claims too, which a probationer can bring today. Running the meeting properly is not just preparation for 2027.

One more detail: an employee only has the right to written reasons for dismissal after two years of service, as Acas notes, except where they are pregnant or on maternity or adoption leave, in which case the right applies from day one. Write the reasons down anyway. If a claim lands, your contemporaneous note is the case.

What to do on Monday

Pull a list of everyone who started between roughly July and December 2026. For each one, work out the date they reach six months of service and put it in your diary alongside their probation review date.

Then, for anyone you have doubts about, hold the honest conversation now rather than in week twenty three. Tell them what is wrong, in writing, with a date by which it needs to look different. Either they improve, which is the outcome you actually wanted, or you have a documented process that stands up whichever side of 1st January 2027 the decision falls on.

The change catches employers who were planning to decide later. It does not catch employers who decided on time.

Tarn.hr provides HR guidance based on UK employment law and Acas codes of practice. It does not constitute legal advice and should not be relied upon as such. Employment law is complex and turns on the facts of each case. For any situation involving significant legal risk, potential tribunal claims, or matters of particular sensitivity, you should seek advice from a qualified employment solicitor. Tarn.hr is not responsible for any decisions made on the basis of its guidance.