Can You Dismiss an Employee on Long-Term Sick Leave with a Mental Health Condition?
Yes, but only once you can show the employment relationship is no longer sustainable despite reasonable adjustments, current medical evidence and proper consultation, and only if the dismissal itself doesn’t amount to disability discrimination. Get any of those wrong and a short-service dismissal that looks straightforward can turn into a costly discrimination claim, which unlike ordinary unfair dismissal has no length-of-service threshold at all.
Why this is riskier than it looks
Employers sometimes assume that if someone hasn’t been employed for two years, they’re free to dismiss for long absence without much process. That’s only true for an ordinary unfair dismissal claim. If the underlying condition meets the Equality Act 2010 definition of disability (a substantial, long-term adverse effect on normal day-to-day activities), the employee can bring a disability discrimination claim from day one of employment, with no service requirement and no cap on compensation. Length of service protects you from one type of claim, not the other.
What has to happen before dismissal is safe to consider
Up-to-date medical evidence. A stale occupational health report from months ago isn’t good enough. You need a current view on diagnosis, prognosis, and a realistic return date, or confirmation that none can be given.
Reasonable adjustments, genuinely tried. Extended absence triggers, a phased return, altered duties, temporary redeployment: whatever was realistic for the role and the business needs to have been considered and, where workable, attempted. A tribunal will look at what you actually did, not what you say you would have done.
Meaningful consultation with the employee. Regular welfare contact through the absence, not just an HR letter every few months, and a genuine conversation before any decision about what would help them return and what the business can realistically sustain.
A considered view on whether the role could be held open, or adapted, for longer. The size and resources of the business matter here. What’s reasonable for a 200-person company is not automatically reasonable for a five-person one, and that cuts both ways in a tribunal’s assessment.
Only once those steps have been taken, and the medical evidence and consultation point to no realistic return in a reasonable timeframe, does dismissal become a defensible option, and even then it should follow a fair, documented process with a right of appeal.
The two claims a badly handled dismissal can trigger
Discrimination arising from disability (Equality Act 2010, s.15). Dismissing someone because of something connected to their disability (their absence) is unlawful unless the employer can objectively justify it as a proportionate means of achieving a legitimate aim, which in practice means showing the adjustments and evidence above.
Unfair dismissal, if the employee has two years’ service (falling to six months for dismissals taking effect from 1 January 2027, under the Employment Rights Act 2025). Even where discrimination isn’t made out, a dismissal that skipped proper process or ignored current medical advice is a well-established route to an unfair dismissal finding.
A practical timeline
- Absence becomes prolonged or a pattern emerges: start occupational health referrals and regular welfare contact, don’t wait for a fixed trigger point.
- Get a considered occupational health or specialist opinion on diagnosis, likely duration and any adjustments that might help.
- Consult properly: share the medical evidence (with consent), discuss what the business can offer, and record the conversation.
- Consider and, where realistic, implement adjustments; review after a set period.
- If there’s genuinely no improvement and no adjustment would make a return realistic, hold a formal meeting, explain the position, give the employee the chance to respond, and confirm the decision and appeal route in writing.
Frequently asked questions
How long does someone have to be off sick before we can start this process?
There’s no fixed trigger. What matters is that the absence is genuinely long-term or recurring to the point the role isn’t being covered sustainably, and that you’ve engaged properly rather than acted on a fixed number of weeks or months.
Do we have to hold the job open indefinitely?
No. Once you’ve made reasonable adjustments and got current medical evidence showing no realistic return, the law doesn’t require an open-ended commitment. What counts as “reasonable” scales with the size and resources of the business.
What if the employee refuses to engage with occupational health?
Document the attempts to engage them, explain why the referral matters, and proceed on the best available evidence if they continue to refuse, while keeping a clear record that the refusal was theirs, not a process failure on your part.
Does it make a difference if they’ve only worked for us for a few months?
For an unfair dismissal claim, yes, short service is currently a defence. For a disability discrimination claim, no: there’s no minimum service requirement, so short-service employees are not automatically lower risk if the condition meets the disability threshold.
This is general information, not legal advice on your specific situation. Every long-term absence case turns on its own facts and medical evidence, so get in touch with Liz Burley and the team before making a final decision.
