The End of Casual Probation

For a long time, UK small businesses operated with a degree of breathing space when it came to new hires. The two year qualifying period for unfair dismissal meant probation was often treated as a loose settling in period rather than a formal assessment. If someone was not quite right, there was time to see whether things improved, often well beyond the initial three or six month probation.

That safety net has now gone.

With the qualifying period for unfair dismissal reduced to six months, probation is no longer informal. It is a defined, high risk window in which decisions need to be made deliberately and on time. Waiting and seeing is no longer a neutral position. It is a legal one.

Why the real deadline is earlier than six months

Although the legislation references six months, in practice the deadline for employers is significantly earlier. If you reach month six and only then conclude that the employee is not the right fit, you are already too late.

In reality, the decision needs to be made by around week 18.

That timing allows employers to properly assess performance and conduct, move into a formal process where required, and serve notice so that employment ends before the employee acquires day one unfair dismissal rights. Leaving this until the final weeks creates unnecessary risk and removes any margin for error.

From informal chats to written evidence

In small teams, performance management is often handled conversationally. A quiet word, a check in over coffee, or an assumption that “they know what we mean”. Historically, this felt proportionate and human.

Under the new framework, that informality becomes a liability.

If an employee reaches the six month point and is then dismissed, the employer must be able to demonstrate a fair reason and a fair process. That means written evidence. Not retrospectively, and not rushed together once things deteriorate, but built from the start.

Every probation review should be documented. That includes early reviews where things appear to be going reasonably well, as well as later reviews where concerns are raised. These records show that expectations were clear, feedback was given, and the employee had a genuine opportunity to improve.

Managing probation as a structured process

A well run probation period now needs clear milestones.

Around month four should act as an amber light. If performance, conduct, or capability is not where it needs to be, this must be addressed clearly and in writing. Vague reassurance followed by sudden dismissal later is exactly the type of situation tribunals scrutinise.

By month five, a decision should be made. If concerns remain unresolved, the employer should move to a formal probation meeting, following a basic but fair process. This is not about being heavy handed, but about being clear and consistent.

Notice periods also matter. Contracts should specify notice during probation, commonly one week. That notice must be issued and expire before the six month anniversary. Serving notice on the last day of month five without allowing it to run its course is not sufficient.

A fair exit still matters

Ending employment before six months does not remove all legal risk. Claims such as discrimination, whistleblowing, or automatically unfair dismissal do not require a qualifying period.

This is why process still matters, even early on. Decisions should be objective, evidence based, and free from assumptions or protected characteristic bias. A structured probation process protects both the business and the individual.

What this means for small business owners

The era of casual probation is over. Recruitment decisions need to be tighter, onboarding needs to be more structured, and probation needs to be actively managed rather than passively observed.

The first 18 weeks of employment should be treated as a defined assessment phase, not an extended trial with no checkpoints. Difficult conversations held early are far less damaging than legal disputes later.

At Saltwater HR, we see probation not as a hurdle for employees, but as a framework that supports fair decision making. Used properly, it allows businesses to act confidently, proportionately, and lawfully, before problems become much harder to resolve.