Some Other Substantial Reason (SOSR): When is dismissal fair?

Most employers are comfortable navigating the “classic” routes to dismissal – disciplinary action for misconduct, or capability processes when someone cannot do the job, for example.

The difficulty comes when the situation doesn’t fit neatly into a specific category: for example, an irretrievable breakdown in working relationships, or an employee being imprisoned for a period that does not legally bring the employment contract to an end. In cases like these, employers often look to dismiss for Some Other Substantial Reason – better known as SOSR.

What is Some Other Substantial Reason (SOSR)?

SOSR is one of five potentially fair reasons for dismissing an employee under UK employment law. It is designed for situations where the employer’s reason is serious enough to justify dismissal, but does not fall within one of the other fair dismissal categories, which are:

• Conduct – where an employee has displayed unacceptable behaviour or actions at work.
• Capability or qualifications – the employee is not able to perform the job due to skill, ill health, or insufficient qualifications.
• Redundancy – when a role is no longer needed.
• Breach of statutory restriction – for example, an employee loses their driving licence and driving is essential to the role.
• Some Other Substantial Reason (SOSR) – a catch-all category for fair dismissal reasons not at 1 – 4 above.

How do Tribunals assess SOSR?

SOSR dismissals have been shaped by case law. In practice, when an employer relies on SOSR, tribunals typically look at two key questions:

• Was SOSR genuinely the real reason for dismissal? (in other words, is it the true reason – not a label applied afterwards?); and
• Was it reasonable to dismiss in the circumstances? This includes whether the employer followed a fair process and whether the decision fell within the “range of reasonable responses” open to a reasonable employer, taking into account the organisation’s size and resources.

Even where SOSR exists, a poor process can still make dismissal unfair.

Common examples of SOSR dismissals

SOSR dismissals cover a wide range of scenarios. Common examples include:

• Breakdown in working relationships – serious personality clashes or persistent conflicts may justify dismissal, but only in severe, business-critical cases.
• Conflict of interest – where an employee’s outside interests or relationships clash with business objectives, such as ties to a competitor.
• Reputational risk – continued employment may harm the organisation’s reputation, particularly in sectors requiring trust or safeguarding.
• Changes to terms and conditions – refusal to accept legitimate, business-driven changes which can lead to dismissal and re-engagement on new terms (“fire and rehire”). Note: reforms banning fire and rehire are expected to take effect from October 2026.
• Temporary cover roles – employees hired to cover leave may be fairly dismissed when the permanent employee returns, if this was made clear from the start.
• Third-party pressure – for example, where a client insists an employee is removed from their work and there is no suitable alternative role available.

When SOSR cannot be used

SOSR cannot justify dismissals that are automatically unfair. This includes dismissals related to statutory rights, such as:

• Pregnancy, maternity, or paternity leave
• Health and safety complaints
• Trade union activity
• Flexible working requests
• Whistleblowing
• Jury service
• Refusal to work excessive hours
• Claims to National Minimum Wage
• Forced retirement.

In these cases, dismissal is unlawful regardless of the employer’s reasoning.

Best practice for SOSR dismissals

Dismissing an employee can be complex and needs to be handled carefully. The process an employer should follow will depend largely on the specific circumstances of the dismissal. There has also been some uncertainty around whether the Acas Code of Practice on Disciplinary and Grievance Procedures applies to dismissals for SOSR. That said, and to help minimise legal risk, employers should generally consider the following steps:

• Investigate all evidence thoroughly and objectively.
• Consider all alternatives to dismissal, including warnings or adjustments to the work environment.
• Consult the employee and allow them to provide representations before making a decision.
• Inform the employee of their right to be accompanied by a colleague or trade union representative.
• Ensure the dismissal decision is made by an appropriately authorised manager and is clearly explained, including notice period and appeal rights.

Employees dismissed under SOSR are usually entitled to full pay for their notice period, whether or not they are required to work it. Garden leave is common, and any outstanding holiday pay, commission, or expenses should also be paid.

Contact our employment law solicitors today

Where there is uncertainty about the process or fairness of an SOSR dismissal, seeking professional legal advice is recommended. Ashtons Legal’s employment specialists can provide guidance and support. Please contact a member of our Employment Law team. You can use our online enquiry form or call 0330 191 5713.