Probation Periods and Fair Dismissal: A Practical Guide for Managers

Probation periods are one of the most misunderstood tools in UK employment practice. Many managers treat them as a kind of legal free pass — a window in which someone can be let go 'no questions asked'. That belief causes real problems, both for the people being managed out and for the organisations that end up defending tribunal claims they thought couldn't happen. This guide sets out what a probation period actually is in law, how to run one properly, what 'fair' dismissal during or after probation genuinely requires, and the current UK reform position as of September 2026 — including the change taking effect from 1 January 2027 that every manager needs to know about now.

Note on scope: employment law differs between the UK and Ireland. This guide focuses on the UK position (Great Britain and Northern Ireland follow broadly similar unfair dismissal principles, though NI's qualifying period and tribunal rules have some differences). Irish employers should check probationary provisions under the Unfair Dismissals Acts and the Employment (Miscellaneous Provisions) Act separately.

What a probation period legally is — and isn't

This is the single biggest misconception to clear up. A probation period is not a separate statutory employment status. There is no law that says 'employees on probation have fewer rights'. A probation period is simply a contractual arrangement — a clause the employer chooses to include in the contract of employment, typically running for three, six, or occasionally twelve months, during which performance and suitability are formally assessed, often with a shortened notice period.

Because it is contractual rather than statutory, probation exists entirely at the discretion of the employer. You can have a three-month probation, a six-month probation, no probation at all, or an extended one — provided the contract is drafted accordingly and applied consistently. What probation does not do is switch off employment protections that exist independently of it.

The two-year qualifying period — and what changes from 2027

The rule that actually governs whether an employee can bring an ordinary unfair dismissal claim is the statutory qualifying period, not the probation clause. As UK law stands through 2026, an employee generally needs two years' continuous service before they can claim ordinary unfair dismissal — regardless of whether they are still 'on probation' or have long since passed it. A dismissal in month four is treated, for unfair dismissal purposes, exactly the same as a dismissal in month twenty-three: neither employee has reached the two-year threshold, so neither can bring an ordinary unfair dismissal claim (subject to the exceptions below).

This is changing. The Employment Rights Act 2025 (the legislation that grew out of the government's Employment Rights Bill) received Royal Assent in December 2025, and the government has confirmed it intends to commence the unfair dismissal reforms from 1 January 2027. Contrary to earlier proposals and a lot of outdated commentary still circulating online, the final change is not a 'day one' right to claim ordinary unfair dismissal. Instead, the qualifying period is being reduced from two years to six months. From that date, an employee will generally be able to bring an ordinary unfair dismissal claim once they have six months' continuous service, rather than two years. The government has also confirmed that the qualifying period for a written statement of reasons for dismissal will drop to six months alongside it, and that the cap on unfair dismissal compensatory awards is being removed entirely.

Two things for managers to hold onto here. First, this has not happened yet — as of today, the two-year qualifying period still applies, and it will continue to apply until the government's commencement date takes effect. Second, when it does land, it is a shortened qualifying period, not a statutory 'light-touch' probation dismissal process. The government's own guidance to employers on this reform explicitly tells businesses to review how their contractual probation periods will interact with a six-month qualifying period, rather than creating a new formal probationary dismissal regime in law. In practice, this means many employers are expected to shorten probation periods to sit within (or close to) that six-month window, and to tighten up how quickly performance issues are identified and addressed.

The exceptions that already apply — no qualifying period, ever

This is where the 'probation means no rights' assumption gets employers into real trouble, both now and after the 2027 change. Two categories of dismissal have no qualifying period at all, and never have:

• Automatically unfair reasons — dismissing someone because they are pregnant or on maternity leave, because they asserted a statutory right, because they made a protected disclosure (whistleblowing), because they sought to exercise working time or trade union rights, or for a handful of other statutorily protected reasons. An employee with one week's service can bring this claim exactly as an employee with ten years' service can.
• Discrimination claims under the Equality Act 2010 — dismissal (or any other treatment) because of a protected characteristic such as sex, race, disability, age, religion or belief, sexual orientation, pregnancy and maternity, gender reassignment, marriage/civil partnership. These claims sit entirely outside the unfair dismissal qualifying period framework and can be brought by an employee on day one.

So a manager who dismisses a five-month employee for, say, raising a genuine safety concern, or shortly after disclosing a pregnancy, or because of a perceived disability, is not protected by the two-year rule (or, from 2027, the six-month rule) at all. The 'they haven't got two years in' reasoning that feels safe is, in these specific circumstances, no defence whatsoever — and these are exactly the situations where tribunals scrutinise the employer's actual reason for dismissal most closely.

Running a probation period properly

A probation period only does its job — protecting both the business and the new hire from a bad long-term fit — if it is actually managed, not just left running in the background until the end date arrives. Good practice looks like this:

• Set clear objectives at the outset. Within the first week or two, agree specific, measurable expectations for the probation period: what 'meeting the bar' looks like by the halfway point and by the end. Vague expectations ('settle in well', 'fit the team') are almost impossible to assess fairly and nearly impossible to defend later.
• Hold regular, structured check-ins. Weekly or fortnightly one-to-ones during probation, not just a single meeting at the end. These should cover progress against the objectives, not just general chat.
• Document feedback as you go. Brief written notes after each check-in — what was discussed, what's going well, what needs to improve — create a contemporaneous record. This is the single most valuable thing a manager can do to support both a positive outcome and, if needed, a fair dismissal decision.
• Build in formal review points. A mid-probation review and an end-of-probation review, each confirmed in writing, give the employee a genuine opportunity to understand where they stand and to improve before any final decision is made.
• Give the employee a real chance to improve. If concerns emerge early, say so early — do not save up a list of problems for the final review meeting.

For a wider view of what good ongoing performance management looks like beyond the probation window, see our guide to managing performance fairly.

What 'fair' actually requires — even where the qualifying period isn't met

Here is the point many managers miss: just because an employee cannot bring an ordinary unfair dismissal claim does not mean the process around their dismissal doesn't matter. It matters for several practical reasons.

• You may be wrong about their service. Continuous service calculations (previous employment with an associated employer, a TUPE transfer, agency-to-employee conversion) can catch employers out. Get it wrong and a dismissal you assumed was 'unchallengeable' turns out not to be.
• The real reason might be a protected one. If the actual or partial reason for dismissal touches on a protected characteristic or a protected disclosure, the qualifying period is irrelevant, as set out above. A properly documented, performance-based rationale is your best defence against a claim that the real reason was something else.
• Natural justice protects the business's reputation and culture, not just against claims. Dismissing someone abruptly, without ever having told them there was a problem, damages trust across the wider team and invites exactly the kind of grievance or public criticism that costs far more in reputation and morale than the process would have cost in management time.
• Consistency matters. If one probationer was given warnings, coaching and an extension, and another in a similar role was dismissed with no warning for a comparable issue, that inconsistency is difficult to explain if a discrimination claim follows — and it is bad management regardless of legal risk.

In practice, 'fair' during probation means: the employee knew what was expected, they were told clearly and promptly when they weren't meeting it, they had a genuine opportunity to improve, the decision-maker considered the situation with an open mind, and the whole process is documented. None of this requires a full disciplinary procedure in every case — probation dismissal can be quicker and lighter-touch than a standard misconduct process — but it does require basic fairness and a clean paper trail. If a probation issue starts to look like a conduct or capability matter that might escalate into formal proceedings, our guide to disciplinary and grievance essentials covers how to keep that process itself fair and defensible.

Extending probation properly

Extending a probation period is often the right call when performance is borderline rather than clearly failing, or when circumstances (a long absence, a change in role scope, insufficient time to properly assess a skill) mean the original window wasn't a fair test. Done properly, an extension:

• Is confirmed in writing, stating the new end date and, critically, the specific reasons for the extension and the specific areas that still need to improve.
• Sets out clearly what 'success' looks like by the new date, so the employee isn't simply given more time with no clearer goalposts.
• Is agreed (or at least clearly communicated) before the original probation end date passes, not retrospectively.
• Checks the contract actually permits an extension — most well-drafted probation clauses do, but it's worth confirming rather than assuming.

Common mistakes employers make

• No real objectives set at the outset, so probation becomes a vague, unstructured 'wait and see' period with nothing concrete to assess against.
• No documented feedback along the way — problems are only raised, if at all, in the final week, leaving no record that the employee was given a fair chance.
• Inconsistent treatment between employees in similar situations, which undermines fairness and creates discrimination risk.
• Assuming the two-year (or future six-month) rule is a blanket shield, and dismissing without proper process where the real or contributing reason may in fact be discriminatory or connected to whistleblowing, pregnancy, or another protected ground — situations where the qualifying period offers no protection at all.
• Poor record-keeping generally, which leaves the employer unable to demonstrate what actually happened if a claim or grievance does arise later. Good documentation practices across HR processes, not just probation, are covered in our guide to records and information management.
• Treating the end-of-probation meeting as a formality rather than a genuine decision point, which can make outcomes look pre-determined.

Frequently asked questions

Can an employer dismiss someone during probation without a reason?

In most cases where the employee has under two years' service (falling to six months from 1 January 2027, once that reform commences), there is no need to show the dismissal met the full statutory 'fair reason' test that applies to longer-serving employees, because the employee cannot bring an ordinary unfair dismissal claim. However, the employer must still not dismiss for an automatically unfair reason or a discriminatory reason, both of which carry no qualifying period, and good practice strongly favours giving a genuine reason regardless.

Does probation affect statutory notice or redundancy rights?

Probation clauses often set a shorter contractual notice period during the probationary window, which is generally lawful provided it meets the statutory minimum notice (currently one week after one month's service). Statutory redundancy pay has its own separate two-year qualifying requirement and is unaffected by probation status.

Is the two-year qualifying period being scrapped entirely?

No — that was an earlier proposal, but the position confirmed in the Employment Rights Act 2025 is a reduction from two years to six months for ordinary unfair dismissal claims, expected to commence from 1 January 2027, not a day-one right. Employers should treat this as the current confirmed position and watch for further guidance from ACAS and gov.uk as the commencement date approaches.

Should we shorten our probation periods ahead of the 2027 change?

Many employers are reviewing exactly this. If your probation period currently runs longer than six months, it's worth considering whether it still gives you a meaningful assessment window once employees gain unfair dismissal rights at six months' service, and whether your review points and documentation practices need to move earlier to match.

Getting probation and early-service dismissals right is as much about good management discipline as it is about legal compliance — and both matter more, not less, as the qualifying period shortens. If you manage people and want a deeper, structured understanding of UK employment law, performance management and HR compliance, explore Learnsignal's accredited CPD courses for practical, up-to-date training built for working managers and HR professionals.