You’ve just hired someone. The interview went well, the references checked out and now they’re sitting at their desk on day one. So why bother with a probation period at all?
Because a good hire on paper doesn’t always turn into a good hire in practice. Probation gives you a structured window to find out how a new employee really performs before you’re fully committed. Done properly, a probation period protects your business. Done badly or ignored entirely, it protects nobody.
This guide is written for UK employers. It covers what probation periods are, how long they should be, how to manage them properly and the changes to unfair dismissal law arriving on 1 January 2027, which make getting probation right more important than ever.
A probation period is a contractual arrangement, not a legal requirement. There’s no law that says you must have one. It’s simply a way of building a trial phase into a new employee’s contract, giving you and them a defined period to assess whether the role is the right fit.
Think of it less like a legal shield and more like a test drive. You wouldn’t buy a car without checking how it handles first. Probation is that check, applied to employment.
During probation, an employee typically has:
What probation does not do is strip away an employee’s statutory rights. They’re still entitled to the National Minimum Wage, statutory sick pay from day one, protection from discrimination and paid holiday from their very first day.
There’s no statutory maximum period. You can technically set a probation period at nine months or even a year, and plenty of senior or specialist roles do exactly that. But longer isn’t automatically better.
Three to six months has historically been the most common range in the UK, and for good reason. It’s long enough to see how someone performs once their initial excitement or enthusiasm wears off, but short enough that you’re not carrying an unresolved decision for half a year.
Here’s the thing some employers get wrong: they default to six months because it feels like the safe, standard option, without thinking it through.
At present, an employee generally needs two years’ continuous service before they can bring an ordinary unfair dismissal claim. Under the Employment Rights Act 2025, that qualifying period falls to six months for dismissals taking effect on or after 1 January 2027.
If you run six-month probation periods, your decision point and the moment an employee gains unfair dismissal protection will land at almost exactly the same time.
The change also applies to people already working for you. Anyone who started before 1 July 2026 will have at least six months’ service by 31 December 2026, so they will be protected from 1 January 2027. Anyone who joined after that is protected as soon as they reach six months.
Two further points raise the stakes:
This is why employment law specialists increasingly recommend three-month probation periods, with the option to extend by a further month if genuinely needed. That keeps your decision comfortably inside the window where dismissal carries the lowest legal risk.
If your template contracts still specify six-month probation as standard, now is the time to review them. Our guide on keeping employment contracts up to date covers this in more detail.
A probation period can only be fair if the employee knows what they are being assessed against. With a shorter window to make a decision, clear expectations matter even more.
In the first week, make sure your new starter has:
If someone later fails probation, being able to show they knew what was expected and were given reasonable support is one of the strongest positions you can be in.
This can often trip up employers. Probation is not a free pass to dismiss without consequence.
Even during probation, some dismissals are automatically unfair regardless of how long someone has worked for you. There’s no qualifying period at all if a dismissal relates to things like:
Discrimination claims under the Equality Act 2010 also require no minimum length of service. If you dismiss someone during week three of their probation and the reason relates to a protected characteristic, such as age, sex, disability, or religion, you’re exposed exactly the same as if they’d worked for you for ten years.
So probation reduces your risk around ordinary unfair dismissal. It does nothing to reduce your risk around discrimination or automatically unfair reasons. That distinction matters, and it’s one that will cause problems for any employers who assume probation means “no risk at all.”
Vague wording causes most of the problems that crop up at a later date. Your contract, or the written statement of employment particulars you’re required to give every new employee, should clearly set out:
If your contract is silent on any of these, you’re leaving room for disputes later. A new manager who wasn’t involved in drafting the original template often assumes probation can be extended indefinitely, or that no notice is required. Neither is usually true, and getting caught out by your own contract’s silence is an entirely avoidable problem.
A probation period without structured check-ins is just an informal waiting game. If you want it to actually do its job, build in reviews from the start.
A workable structure looks like this:
Document each of these, even briefly. Not because you’re expecting a dispute but because if one does arise later, a paper trail showing genuine fair engagement with the employee’s performance is worth far more than your recollection of a conversation from four months ago.
Sometimes three months isn’t quite enough to reach a clear decision. Extending is fine, as long as your contract allows for it and you communicate the extension and the reasons for it, clearly and in writing before the original period ends.
What you shouldn’t do is let probation quietly run past its end date without any formal extension or confirmation. If the contract says probation ends after three months and nothing else happens, most employees will reasonably assume they’ve passed, regardless of what you privately intended.
If probation isn’t working out, the process still needs to be fair, just proportionate to the circumstances.
You don’t need the full disciplinary process you’d run for a long-serving employee, but you do need:
Skipping straight to dismissal with no prior conversation at all is where employers could get caught out, particularly once the six-month unfair dismissal threshold arrives in 2027. Even now, a completely undocumented, out-of-nowhere dismissal invites exactly the kind of dispute a good probation process is meant to prevent.
If you’re a small business without a dedicated HR function, this is the kind of change that’s easy to miss until it’s already affecting you. Practical steps to take now:
Probation periods are a contractual tool, not a legal requirement, and they don’t remove an employee’s day-one rights around discrimination or automatically unfair dismissal. From 1 January 2027, unfair dismissal protection starts at six months and compensation is uncapped, so the traditional six-month probation period becomes a real risk. Shorter periods, clear objectives and documented reviews are fast becoming best practice.
Get your contracts, review process and managers’ understanding sorted now, rather than scrambling once the new rules are in force.
If you’re managing this without in-house HR support, a pay-as-you-go HR service can review your current contracts and probation process without committing you to an ongoing retainer. For businesses hiring more regularly, it may be worth comparing the costs of ad hoc support against a fixed HR package.
No. There’s no law requiring employers to use probation periods. They’re a contractual arrangement you choose to include and their terms, length and process are entirely up to what you set out in the employment contract.
It gives you a defined window to assess a new employee’s performance, skills and fit before confirming them in the role. From 2027, three months also leaves a safe margin before unfair dismissal protection begins at six months.
Generally yes, a shortened, proportionate process is acceptable during probation if the employee hasn’t reached the qualifying period for unfair dismissal. However, you still need a genuine reason and you must be careful the reason isn’t linked to discrimination or an automatically unfair ground, since neither requires any minimum length of service to claim.
This depends on your contract. Many employers set a shorter notice period during probation, often one week, rising to the standard contractual notice once probation is successfully completed. The statutory minimum during the first two years of employment is one week, but your contract can specify something different as long as it doesn’t fall below that statutory floor.
Yes. Employees on probation are entitled to statutory sick pay from the first day of absence, if they meet the eligibility rules. Your contract can limit enhanced company sick pay during probation, but not statutory sick pay.
There’s no legal limit on how many times you can extend probation, provided your contract allows for extensions and you communicate each one clearly in writing. That said, repeated extensions without a clear decision start to look less like genuine assessment and more like avoidance, which can work against you if a dispute arises later.
The biggest mistakes are skipping reviews, raising concerns for the first time at the end, letting probation run past its end date without confirmation, and forgetting that discrimination protection applies from day one.
From 1 January 2027, employees gain unfair dismissal protection after six months’ service rather than two years, and compensation is no longer capped. If your probation periods run to six months, you’ll have little or no margin to act. A three-month probation with an option to extend gives you a safer buffer.
