Probation Period Rules UK: What Employers Need to Know

A probation period is one of the most useful tools a small employer has - but only if it is set up and used correctly. Many employers assume that because an employee is on probation they have no rights and can be dismissed without consequence. That assumption is wrong and from January 2027 it becomes significantly more dangerous. This guide tells you exactly what probation periods can and cannot do.

What a probation period is

A probation period is a defined period at the start of employment during which the employee's performance, conduct and suitability for the role are assessed. It is a contractual arrangement - it exists because your employment contract says it does, not because of any law that requires it.

The most common length is three to six months. Some employers use twelve months for senior roles. There is no legal maximum, but the longer the probation period, the less useful it becomes as a management tool.

During probation, the same employment rights that apply throughout employment apply - but currently, the two-year qualifying period for unfair dismissal means that employees in their first two years have limited tribunal recourse if dismissed. This changes significantly from January 2027.

What probation can do

A well-drafted probation clause in your employment contract gives you two practical advantages.

First, it allows a shorter notice period during the probationary phase - typically one week on either side - which makes parting ways with a poor hire less costly.

Second, it creates a natural review point that is written into the contract. This makes it easier to have honest performance conversations early, because both parties know a formal review is coming.

What probation cannot do

A probation period does not remove the employee's right not to be dismissed for a discriminatory reason. You cannot dismiss someone during probation because they are pregnant, because of their race, religion, disability or any other protected characteristic. Discrimination claims have no qualifying period - they can be brought from day one.

A probation period does not allow you to pay below the National Minimum Wage. It does not remove the entitlement to SSP. It does not suspend the right to a written statement of employment particulars.

And from January 2027, a probation period of six months or less will not protect you from an unfair dismissal claim. An employee who completes a standard three or six-month probation and is then dismissed in month seven will have full tribunal rights.

How to fail someone's probation

Failing someone's probation - ending their employment because they have not met the required standard - is legally straightforward if done correctly. It becomes problematic when employers treat it as an administrative formality rather than a managed process.

Throughout the probation period, give the employee regular feedback. Do not wait until the final review to raise concerns that have been apparent for weeks. If performance or conduct is not meeting the required standard, tell them - in writing - and give them the opportunity to improve.

If you decide not to confirm the employment at the end of probation, tell the employee in writing before the probation end date. The letter should state that the probation has not been passed, give the reason, confirm the notice period and confirm the date employment ends.

For short probation dismissals with straightforward performance concerns, you do not need to follow a full disciplinary process. But you do need to have been fair - regular feedback, clear expectations, a genuine opportunity to meet the standard.

How to extend a probation period

You can only extend a probation period if your contract includes a clause that allows it. Many standard contracts include an extension provision of up to three months.

If you are extending, send a letter before the original end date. State the reason for the extension, the targets the employee must meet during the extended period and the new end date. Make the targets specific and measurable.

Do not extend probation indefinitely or repeatedly. If an employee is so unsuitable that you cannot confirm their employment after nine or twelve months, the issue is not the probation - it is that you have not taken the decision to part ways.

Probation periods and the January 2027 change

What to do now

Review your employment contracts. Check that your probation clause includes an extension provision and a shorter notice period during probation. Make sure the probation period is defined in months, not weeks.

Build a review process. A structured mid-probation check-in and a formal end-of-probation review, both documented, give you the evidence of a fair process if a claim is ever made.

Do not wait until January 2027 to make these changes. The employees you hire today will be subject to the new rules within months of starting.

How Birchlow helps

Birchlow keeps your employment contracts and probation clauses updated automatically as employment law changes. When the January 2027 qualifying period reduction comes into effect, your contracts are updated before it happens - not after. The platform also generates the probation outcome letter and extension letter when you need them.