How the 2026 Employment Law Changes Are Raising the Standard for Workplace Investigations

Workplace investigations have always been a critical component of fair employee relations. However, recent employment law developments in 2026 are significantly increasing the expectations placed on employers when conducting them.

Guidance highlighted by Chartered Institute of Personnel and Development and industry commentary indicates a clear shift: investigations are no longer viewed as an internal administrative step, but as a central element in determining whether an employer has acted reasonably and lawfully.

For SMEs, this represents a meaningful change. Informal or inconsistent approaches that may previously have gone unchallenged now carry greater risk.

The direction of employment law reform reflects a broader emphasis on:

• Early employee protections

• Fairness and transparency

• Employer accountability

With changes such as reduced qualifying periods for unfair dismissal and expanded day-one rights, employees are able to challenge decisions much earlier in their employment.

This means that the quality of the investigation underpinning any decision is more likely to be examined.

Historically, many SMEs have approached investigations in a relatively informal way, particularly where issues appeared straightforward.

This often includes:

• Relying on verbal accounts

• Limited documentation

• Combining investigation and decision-making roles

• Moving quickly to outcomes without fully establishing facts

While this approach may have been sufficient in lower-risk scenarios, the current legal landscape requires a more structured and demonstrable process.

The increased expectations around investigations can be summarised across four key areas:

1. Greater Emphasis on Impartiality

Employers are expected to ensure that investigations are conducted objectively.

This includes:

• Avoiding conflicts of interest

• Separating investigation and decision-making roles where possible

• Approaching evidence without predetermined conclusions

In smaller organisations, this can be challenging, but the expectation remains that reasonable steps are taken to ensure fairness.

2. More Robust Evidence Gathering

Investigations should not rely on assumptions or limited information.

Employers should:

• Gather relevant documentation

• Interview all appropriate parties

• Consider both supporting and contradictory evidence

A failure to do so can undermine the credibility of the outcome.

3. Clear and Comprehensive Documentation

Documentation is increasingly central to demonstrating that a fair process has been followed.

Employers should maintain records of:

• Allegations raised

• Evidence gathered

• Interviews conducted

• Decisions made and the rationale

Without this, it becomes difficult to evidence that the investigation was reasonable.

4. Proportionality and Thoroughness

Investigations should be proportionate to the seriousness of the issue.

However, even relatively minor matters require:

• A basic level of structure

• Clear documentation

• Fair consideration of all parties

The threshold for what is considered “reasonable” is rising.

In many employment tribunal cases, the investigation process is a central focus.

Tribunals will consider:

• Whether the employer genuinely established the facts

• Whether the investigation was reasonable in the circumstances

• Whether the process was fair and unbiased

Even where there is a valid reason for disciplinary action, a flawed investigation can lead to findings of unfair dismissal.

Based on common practices, SMEs are most exposed in the following areas:

Lack of a Defined Investigation Process
Without a clear process, investigations can vary significantly depending on the manager involved.

Insufficient Training for Managers
Managers may not understand:

• What constitutes a fair investigation

• How to gather evidence

• How to document findings

Combining Roles
The same individual may investigate, decide, and communicate the outcome, increasing the risk of perceived bias.

Inadequate Record Keeping
A lack of written records can significantly weaken an employer’s position.

1. Introduce a Clear Investigation Framework

Employers should have a defined process that covers:

• How investigations are initiated

• Who conducts them

• How evidence is gathered

• How findings are documented

2. Separate Roles Where Possible

While not always feasible in smaller businesses, employers should aim to:

• Separate investigation from decision-making

• Involve a different individual in appeals

3. Train Managers on Investigation Standards

Managers should understand:

• The importance of impartiality

• How to conduct interviews

• How to assess evidence

• How to document findings

4. Use Structured Templates

Templates for:

• Investigation notes

• Witness statements

• Outcome reports

Help ensure consistency and reduce the risk of omissions.

5. Align Investigations with Policies

Investigations should form part of a wider disciplinary or grievance process, aligned with the ACAS Code of Practice.

An employee raises a grievance regarding workplace behaviour.

The manager speaks to the individuals involved informally and makes a decision without conducting a structured investigation or keeping records.

The employee later challenges the outcome.

The employer is unable to demonstrate:

• What evidence was considered

• How conclusions were reached

• That the process was impartial

This significantly increases the risk of a successful claim.

The 2026 employment law changes are increasing the importance of workplace investigations as a core component of fair process.

For employers, particularly SMEs, the focus should shift towards:

• Structure

• Consistency

• Documentation

• Manager capability

An investigation is no longer simply a step in the process. It is often the foundation on which the entire decision is judged.