Probation periods in the United Kingdom: best practice
Reviewed by Mellow Editorial Team, HR & payroll content team
Probation periods give employers a structured way to assess a new hire before confirming permanent employment. They are not a legal requirement in the UK, but used well they protect both sides — the employer gets a clear evaluation window, and the employee gets transparent expectations from day one.
What the law says about probation periods
There is no statute that defines or mandates a probation period. It is a contractual arrangement, which means the rules are whatever the written contract says — provided they do not conflict with employment law.
What the law does say matters here. Under the Employment Rights Act 2025, employees have strengthened day-one rights. Unfair dismissal protection no longer requires two years of continuous service in the way it previously did, so the assumption that you can dismiss freely during probation no longer holds. Employees also have day-one rights to a written statement of particulars, statutory sick pay, and family leave entitlements regardless of whether they are on probation.
In short, probation does not create a legal grace period. It creates a structured management process.
How long should a probation period be?
Three to six months is the most common range in the UK. Six months is standard for senior or complex roles where it takes longer to assess impact. Some employers use a three-month period with an option to extend by a further three months if concerns arise.
Whatever length you choose, state it clearly in the contract. Also state what happens at the end: confirmation of employment, extension, or termination. Leaving this vague causes disputes.
What good probation management looks like
A probation period is only useful if you actively manage it. Here is what that means in practice.
Set clear objectives at the start. Write down what the employee needs to achieve or demonstrate by the end of probation. These should be specific and realistic — not a vague expectation that they will "fit in".
Schedule check-ins. A formal review at the midpoint and at the end is a minimum. Informal catch-ups in between mean there are no surprises at the final review. If performance concerns arise at week two, raise them at week two — not week eleven.
Document everything. Notes from meetings, written feedback, and any agreed action plans create a clear record. This protects you if a dismissal is later challenged and helps the employee understand where they stand.
Give honest feedback. Probation reviews that consist only of positive comments, followed by a surprise dismissal at the end, are poor management and legally risky. If performance is below standard, say so clearly and give the employee a fair chance to improve.
Extending a probation period
Extension is a reasonable option when performance has been mixed or when the employee has had a period of absence that limited your ability to assess them properly. It is not a way to delay a decision indefinitely.
If you extend, put the extension in writing, specify the new end date, and set out exactly what needs to improve. An open-ended extension — "we'll review again in a few weeks" — creates uncertainty and can complicate things if you later need to dismiss.
Ending employment during or at the end of probation
Dismissal during probation still requires a fair process. Given the strengthened day-one rights under the Employment Rights Act 2025, employers should:
- Give the employee notice as specified in the contract, or statutory minimum notice if the contract provides less (the statutory minimum is one week after one month of service)
- Hold a meeting to explain the concerns
- Allow the employee to respond
- Confirm the outcome in writing
Skipping these steps because "they're on probation" is the most common mistake employers make. A dismissal that appears procedurally unfair, or that could be linked to a protected characteristic, carries real legal risk regardless of length of service.
Probation periods and payroll
Probation periods have no direct effect on payroll obligations. From day one, you must deduct income tax and National Insurance through PAYE, report pay to HMRC via a Full Payment Submission on or before each payday, and pay at least the National Minimum Wage. Pension auto-enrolment assessment happens at the normal trigger points — being on probation does not defer or change that obligation. Some employers choose to hold back non-contractual benefits such as a bonus scheme or enhanced sick pay until probation is passed; that is a legitimate approach provided it is clearly set out in the contract and does not affect statutory entitlements.
This article provides general information only and is not legal advice. If you are dealing with a specific situation, seek advice from an employment lawyer or HR professional.
---
Run HR and payroll in United Kingdom with Mellow
Mellow brings HR, payroll and 12 AI agents into one platform — built to handle United Kingdom properly, with payroll included, from £4 per employee per month. The AI agents don't just answer questions; they generate contracts, run cost estimates and draft letters for you.
- United Kingdom payroll software
[Start a free trial →](/register)