When employers think about unfair dismissal claims, they often picture a disciplinary dismissal involving serious misconduct.

In reality, many unfair dismissal claims arise from ordinary workplace situations:

Underperformance.
Attendance issues.
Personality clashes.
Breakdown in working relationships.
Restructuring and organisational change.

The forthcoming reforms may mean that all of these situations carry greater risk than before.

Key takeaway

A fair reason for the termination of employment is required to answer a claim for unfair dismissal. However, the importance of the reason for termination of employment, even during the probationary period, should not be overlooked.

Probation Will Become More Important Than Ever

Many employers currently view probation as an introductory period during which concerns can be addressed relatively informally. That approach may become increasingly difficult to justify. As employees acquire unfair dismissal rights sooner, organisations will need to identify concerns earlier, document them properly and ensure that managers are trained to handle difficult conversations effectively. Probation periods may no longer be viewed as administrative processes. Instead, they may become critical risk-management tools.

Managers Become the First Line of Defence

To avoid incurring a potential claim for unfair dismissal after 1 January 2027, a decision to terminate employment will need to be made and implemented with statutory notice, within 6 months of the commencement of employment. This requires effective use of the probationary period. But there are often reasons why this might not occur.

Managers may be unaware of the process required to assess the employee within the time available, they may want to avoid a difficult conversation, reviews may be missed, pressure of work may make it difficult to devote the necessary time to the process or the need to start the recruitment process again would be best avoided.

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A probationary period dismissal does not require the same rigour as a disciplinary procedure or a capability procedure required for an employee who has the right to bring an unfair dismissal claim. However, the same principles apply. There needs to be a clear reason why the employer considers that the employee does not meet the standard required for the job. And there needs to be evidence of this. That requires clarity around what the requirements of the role are and as to why these requirements are not being met. Following good record-keeping processes and good procedures in terms of meetings and communication with the employee in question will be of considerable assistance in showing that the decision has been taken in the right way.

Why does this matter?

Not all claims to an employment tribunal require the employee to have been employed for a particular period of time. Some claims are known as "day-one rights". If an employee who is dismissed during their probationary period alleges that the reason for the dismissal is one of these rights, then they can bring a claim for this reason, even if they cannot commence an unfair dismissal claim. This is most often the case with claims of unlawful discrimination.

An employee alleging that their dismissal, or some other treatment during their probationary period was unlawful on prohibited grounds, may make a complaint, requiring the employer to deal with this through their grievance procedure. That may be difficult and time-consuming in the six-month period before the right to bring an unfair dismissal claim arises. A well-managed probationary process with good documentation, evidence and communication is likely to be of considerable importance in circumstances of this kind.

Fair Reasons for Dismissal: frequently asked questions

What makes a dismissal unfair?

A dismissal may be unfair where the employer:

Does not have a potentially fair reason for dismissal.
Fails to investigate adequately.
Does not follow a fair procedure.
Acts inconsistently.
Reaches a decision that falls outside the range of reasonable responses.

Often, disputes arise not because there was no reason for dismissal but because the process followed was deficient.

Why are investigations so important?

The quality of an investigation often determines whether an employer can successfully defend a claim. A good investigation should establish the relevant facts, gather evidence fairly and create a clear record of the decision-making process.

Poor investigations are one of the most common weaknesses identified in employment tribunal proceedings.

What records should employers keep?

Employers should maintain clear records of:

Probation reviews.
Performance discussions.
Informal and formal warnings.
Investigation meetings.
Disciplinary hearings.
Appeal decisions.

Good documentation helps demonstrate that decisions were reasonable and procedurally fair. Well-documented probation reviews are one of the strongest defences against an unfair dismissal claim arising during probation.

Are small businesses affected by these changes?

Yes. The changes in unfair dismissal brought about the Employment Rights Act 2025 apply to employers of all sizes. In many cases, smaller businesses face greater challenges because they often have fewer HR resources and less formalised procedures.

How can employers dismiss an employee fairly?

A fair dismissal requires a potentially fair reason, a reasonable investigation and a procedure that is applied consistently. This applies whether it is a probation period dismissal or a longer-serving employee, though what counts as a reasonable procedure will differ depending on length of service and the reason for dismissal.

How should employers manage absence or performance-related dismissals?

Absence and performance issues should be addressed through a structured process — regular reviews, clear communication of expectations and a documented improvement period — before a decision to dismiss is made. Skipping these steps is one of the most common sources of performance management dismissal risk.

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About the author

Michael Pope is Head of Employment and Corporate Commercial Specialist at Grant Saw Solicitors, where he leads the development of the firm's Business Services practice. With over four decades' experience, he advises businesses, directors and contractors on employment law, risk management, and company and commercial matters.

Michael began his career at Woolsey Morris & Kennedy Solicitors in 1983, becoming a partner in 1987, before founding Lawbridge Solicitors in 2008. He holds a Masters in Employment Law and Relations with Distinction from the University of Leicester and is regulated by the Solicitors Regulation Authority (SRA No. 128429).

Our Employment team advises businesses, directors and contractors across London and beyond on employment law, risk management and the practical implications of legislative change. To discuss a review of your organisation's current position, call 020 8858 6971 or email employmentenquiries@grantsaw.co.uk.

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Disclaimer

This article is for general information only and is not legal advice. Laws and guidance change and outcomes depend on facts. If you need advice on your situation, please contact us. Grant Saw Solicitors LLP is authorised and regulated by the Solicitors Regulation Authority.

Last updated: 21 September 2026

Fair reasons for dismissal in the new employment landscape

Key takeaway

Probation Will Become More Important Than Ever

Managers Become the First Line of Defence