From 1 January 2027, the qualifying period for ordinary unfair dismissal protection in the UK will drop from two years to just six months. For employers, this is one of the most significant shifts in employment law in over a decade, and it fundamentally changes how probation and early-stage performance management need to work.
If your organisation still relies on a leisurely six-month or one-year probation period, or on the old assumption that new hires carry little legal risk for their first two years, this is the moment to rethink that approach. This guide walks through what is changing, when it takes effect, and how to build a probation process that protects your business while treating new employees fairly.
The Employment Rights Act 2025 received Royal Assent on 18 December 2025, and its provisions are being introduced on a staggered basis through 2026 and into 2027. The changes to unfair dismissal are among the last tranche, and they are also among the most consequential for HR teams.
Two changes matter most here:
It’s worth noting how this compares to the original proposal. When the Employment Rights Bill was first published, the headline plan was to make unfair dismissal a genuine “day one” right, removing the qualifying period altogether. That proposal was contested heavily in Parliament, and after several rounds of back-and-forth between the Commons and the Lords, the government settled on the six-month compromise instead. So this is not full day-one protection, but it is a substantial acceleration from where things stand today.
The government has also removed the power to vary the qualifying period through secondary legislation. Any future government wishing to change it again will need to pass primary legislation, a much higher bar. In other words, six months is likely to be the settled position for the foreseeable future, not a temporary staging post.
The rule change formally applies from 1 January 2027, but its practical effect starts earlier, because it applies retrospectively to service already accrued.
Anyone who is continuously employed and has already reached six months’ service by 1 January 2027 gains unfair dismissal protection immediately, on that date. Working backwards, that means any employee hired on or before 1 July 2026 will have banked their six months by the time the new rule takes effect, and will therefore gain protection the moment the law changes, regardless of when their probation review actually happens.
Anyone hired after 1 July 2026 will simply gain protection once they individually reach six months of continuous service, whenever that falls.
There is also a timing trap worth knowing about. Because statutory minimum notice periods count towards continuous service in most circumstances, a dismissal decision made too close to the six-month mark can inadvertently push the employee’s effective termination date past the threshold, meaning they acquire protection they were never meant to have during that window. Employers who wait until five months and three weeks to act may find the notice period alone is enough to tip an employee into protected territory. Building in a genuine margin, rather than cutting it fine, is now essential.
It’s important not to read the six-month change as meaning new employees have no rights at all during their first months. That has never been true, and it remains untrue under the new Act.
Discrimination protections, and protection against automatically unfair dismissal (for example dismissals connected to whistleblowing, pregnancy and maternity, or asserting a statutory right) remain day-one rights. These have never depended on length of service and are not touched by this reform. A poorly handled dismissal in week two can still result in a successful tribunal claim if it touches on a protected characteristic or an automatically unfair reason. The six-month change narrows the gap for ordinary unfair dismissal specifically; it doesn’t create a genuinely risk-free zone at any point in the employment relationship.
Here’s a detail that catches many employers out: the Employment Rights Act 2025 does not actually regulate probationary periods at all. There is no statutory concept of probation in the Act. Probation remains a matter of contract, set entirely by the employer.
What has changed is the context in which probation now operates. Historically, a standard six-month probation period sat comfortably inside a two-year buffer during which unfair dismissal risk was low. Under the new regime, a six-month probation period runs right up against the exact point at which the employee gains statutory protection. There is no longer a safety margin baked in by default.
This means probation now has to do more work. It is no longer just an onboarding formality, it is the primary tool employers have for assessing suitability and making a considered decision before unfair dismissal risk materially increases. Decisions that could previously be revisited or delayed at month four or five, with relative flexibility, now need to be made and acted on earlier, with far better documentation behind them.
Getting the paperwork right from day one also matters for probation. See our complete new employee starter form checklist to make sure nothing’s missed before a new hire’s first day.
Given the compressed timeline, we recommend moving away from the traditional six-month probation model in favour of a shorter, more structured approach:
This structure gives you enough time to properly assess performance, while leaving a genuine margin before the six-month qualifying threshold, including the notice-period trap described above. A final decision made at or before the five-month mark, with an extension built in from month three rather than month five, leaves considerably more breathing room than a straight six-month probation ever did.
Hold a structured meeting within the employee’s first week to:
This single meeting does a lot of the heavy lifting for tribunal defensibility later. If a dismissal is ever challenged, being able to show the employee understood the standard expected of them from day one is powerful evidence of a fair process.
Hold formal review meetings at the end of month one and month two. At each review:
Informal, undocumented “chats” are no longer sufficient. Tribunals scrutinising early-stage decisions will expect to see a paper trail showing concerns were raised promptly and consistently.
Schedule a formal final review in the last week of the initial probation period (building in some flexibility around the exact date, in case either party can’t make it). This meeting should determine whether the employee:
Where an extension is genuinely justified, make sure you can evidence:
Schedule further review meetings within the extension period itself, so progress against the plan is tracked, not just assumed.
If performance still isn’t at the required standard, aim to make a final decision around the five-month point, leaving margin for statutory notice. Notice should be issued in line with the contract, and structured so it does not tip the employee’s effective service past six months.
Even so, process fairness still matters enormously, even for short-service employees who fall below the unfair dismissal threshold. A dismissal that looks discriminatory, inconsistent, or procedurally sloppy can still generate a claim on other grounds, and increasingly, tribunals are scrutinising early-stage decision-making more closely regardless of qualifying service.
Even during probation, offering a right of appeal or review is worth the administrative effort. It:
The common thread running through all of this is documentation. Employers can no longer treat the early months of employment as a low-risk, informal period. The Act compresses the window in which suitability decisions have to be made, which means:
Poorly managed or entirely informal probation processes, which may have been survivable under the old two-year buffer, are likely to be significantly more exposed under the new regime.
Getting ahead of this change now, well before the 1 January 2027 deadline, is far easier than scrambling to fix contracts, policies, and manager training once the new rules are already in force.
At Centric HR, we help employers review and rebuild their probation frameworks so they’re fit for purpose under the Employment Rights Act 2025, including updating contracts and offer letters, training line managers to run structured, well-documented review meetings, and building improvement plans that stand up to scrutiny.
If you’d like support reviewing your probation policy, employment contracts, or manager training ahead of the January 2027 changes, get in touch with the Centric HR team to talk through your options.
This article is intended for general information purposes only and does not constitute legal advice. Employment law is subject to change as further regulations and guidance are published ahead of implementation; employers should seek independent legal advice before updating contracts or policies.
