HEALTH AT WORK

For Employers

Can a Worker Be Dismissed While on Long-Term Sick Leave?

12 September 2026 · Health at Work · AI-assisted draft

Photo: Mikhail Nilov / Pexels

The question arrives on every HR desk eventually: a worker has been absent for months, medical certificates keep coming in, the role is under pressure, and nobody knows when — or whether — the person will return. Can that worker be dismissed? The short answer is yes, but the conditions that make such a dismissal lawful are specific, demanding, and easily mishandled. Get them wrong and the dismissal becomes unfair, exposing the organisation to legal and reputational consequences that dwarf the original problem.

This article sets out what employers need to understand, what they are required to do, and what the most common mistakes look like — before a decision is made that cannot be undone.

What 'Long-Term Sick Leave' Actually Means in Practice

There is no universal definition of how many weeks of absence become 'long-term', but in most employment frameworks the threshold where enhanced employer duties arise sits somewhere between four and twelve weeks of continuous absence. What matters more than the calendar is whether the underlying condition is serious, whether a return date is realistic, and whether the condition may meet the threshold for a disability under applicable law — because if it does, a completely different set of obligations applies before any dismissal can be considered.

Long-term absence is overwhelmingly caused by a cluster of conditions: musculoskeletal disorders (back, joint and soft-tissue injuries), mental health conditions including depression, anxiety and burnout, neurological conditions, cancer treatment, cardiac events, and chronic fatigue syndromes. The occupational health dimension is critical here: many of these conditions were caused or worsened by work, which strengthens the worker's position and adds an additional layer of employer duty.

The Core Legal Principle: Capability, Not Conduct

In most jurisdictions, dismissing someone because they are sick is not treated as misconduct dismissal — the worker has not done anything wrong. The lawful basis, where one exists, is capability: the worker is unable to do the job, and there is no reasonable prospect of that changing within a timeframe the organisation can sustain. This distinction matters enormously. A capability dismissal requires a process that is fundamentally different from a disciplinary one. Treating long-term absence as a conduct matter — giving warnings for being ill, for example — is one of the most reliable ways to make an eventual dismissal unfair.

Across most employment law frameworks, the employer is required to demonstrate four things before a capability dismissal will be considered lawful: that the absence is genuinely ongoing and substantial; that a proper investigation into the medical position has been carried out; that the employer considered all reasonable adjustments or alternatives to dismissal; and that a fair procedure was followed throughout, including giving the worker an opportunity to be heard.

The Occupational Health Assessment: Why It Is Not Optional

Obtaining an independent occupational health assessment is not a formality. It is the factual foundation on which everything else rests. Without it, an employer is making a decision about a person's health without understanding it — and tribunals and labour courts treat that as procedurally fatal in almost every jurisdiction.

A properly conducted assessment should answer the following questions: What is the worker's current clinical condition? Is there a realistic prognosis for recovery, and over what timeframe? Can the worker return to their existing role, or only to a modified one? Are there adjustments to duties, hours, environment or equipment that would make a return possible? Does the condition qualify as a disability, triggering additional employer obligations? The assessment should be carried out by a qualified occupational health practitioner — someone who understands both the clinical picture and the demands of the specific job. A letter from the worker's own treating physician is useful but does not substitute for an independent assessment, because that physician has no knowledge of what the role requires.

Once the report is received, the employer must act on its findings in good faith. Commissioning a report and then ignoring its recommendations — particularly where adjustments are suggested — is one of the clearest indicators of procedurally unfair dismissal.

Reasonable Adjustments: What Employers Are Actually Required to Consider

Before dismissal can be contemplated, employers in virtually every jurisdiction are required to explore whether reasonable adjustments could enable the worker to return. 'Reasonable' is not the same as 'easy' or 'cheap' — it means proportionate to the size of the organisation and the nature of the role. Adjustments that are routinely expected include: phased return to work over a structured period, often four to eight weeks; reduced or modified hours, including part-time arrangements; reallocation of specific tasks that the worker can no longer perform; relocation to a different role within the organisation that is within the worker's capability; provision of specialist equipment, ergonomic adaptations, or assistive technology; and adjustments to supervision or reporting arrangements where the condition affects concentration or communication.

The employer is not required to create a role that does not exist or to remove the essential functions of the job entirely. But the bar for having genuinely explored alternatives is higher than many employers assume. Sending a letter asking 'are you able to return?' and receiving no positive reply does not constitute an exploration of adjustments. A face-to-face meeting — or a formal consultation call if attendance is impossible — must take place before any dismissal decision is reached.

The Procedure That Must Be Followed

Even when the medical evidence is clear and alternatives have been genuinely explored, the procedure still matters. A worker dismissed without having been given the chance to respond to the employer's concerns — including the possibility of dismissal — will almost always have grounds to challenge that dismissal on procedural grounds alone, regardless of what the medical evidence said.

The minimum process in most frameworks includes: keeping regular, documented, supportive contact with the absent worker throughout the absence (not just at the point of crisis); holding a formal absence review meeting where the employer explains its position, shares the medical findings, and invites the worker to respond; allowing the worker to be accompanied by a colleague or representative at that meeting; clearly communicating that dismissal is being considered and giving the worker a genuine opportunity to propose alternatives; and offering a right of appeal against any dismissal decision. Documentation of every stage is not optional — it is what protects the employer if the decision is later challenged.

When Dismissal Becomes Lawful

A dismissal on capability grounds is more likely to be considered lawful when all of the following are true: the absence has been prolonged and shows no clear end point based on objective medical evidence; the occupational health assessment finds no realistic prospect of return within a reasonable period; all feasible alternatives have been genuinely considered and found impracticable; a fair and documented procedure has been followed; and the worker has been given every opportunity to engage and respond. Even then, dismissal is never automatic — it is the outcome of a process, not a response to an absence reaching a particular length.

Employers sometimes focus on length of absence as though it were itself the trigger. It is not. A worker absent for seven months with a clear recovery trajectory and a return date confirmed by occupational health is in a very different position from a worker absent for four months with a permanent or indefinitely progressive condition. Length is one input; prognosis, adjustability and procedural integrity are the others.

Common Mistakes That Make a Lawful Situation Unlawful

Certain patterns appear repeatedly in cases where employer decisions are later found to be unfair. Stopping sick pay abruptly without warning, and then treating financial pressure on the worker as evidence that they are 'choosing' not to return, is manipulative and will be seen as such. Making the dismissal decision before the occupational health report is received — and then treating the report as a post-hoc justification — is procedurally indefensible. Failing to treat a condition as a potential disability because 'it does not look like one' ignores the fact that many mental health conditions, chronic pain syndromes and episodic conditions carry full disability status under most legal frameworks. And using absence management policy as a shortcut — triggering dismissal because a trigger point has been reached without carrying out the individual assessment the situation requires — is among the most frequently challenged approaches in employment litigation.

The Role of Occupational Health in Protecting Both Parties

Occupational health sits at the centre of every long-term absence situation that is handled well. Not because it provides a route to dismissal, but because it provides facts: a clear clinical picture, a realistic prognosis, and a set of recommendations that both employer and worker can use to make decisions. When occupational health is involved early and continuously — not summoned only when dismissal is being considered — outcomes improve for everyone. Workers return sooner and more sustainably. Employers make decisions based on evidence rather than frustration. And the process, if it ultimately leads to dismissal, is demonstrably fair.

Health at Work provides independent occupational health assessments specifically designed to give employers and workers the clarity they need during long-term absence situations — including fitness-for-work reports, recommended adjustments, and phased return planning. Early referral almost always produces better outcomes than late referral, for both sides of the employment relationship.