When is a dismissal for long-term sickness fair in the UK?

The short answer

Long-term sickness can be a fair reason to dismiss — under section 98(2)(a) of the Employment Rights Act 1996, capability is one of the five potentially fair reasons. But whether a specific dismissal is fair under section 98(4) depends almost entirely on the process the employer followed. Tribunals look at four things: medical evidence, consultation, adjustments, and alternatives. Get any of them wrong and a real capability case becomes an unfair dismissal claim.

Disability discrimination claims often run alongside — the long-term nature of most "long-term sickness" cases means the condition usually meets the Equality Act 2010 definition of disability.

The four things tribunals look at

1. Current medical evidence

The single most common failure: dismissing on the basis of an out-of-date occupational health report. What counts as "out of date" depends on the condition, but as a rule of thumb anything older than three months is on shaky ground in a capability dismissal, and anything older than six months is almost certainly stale.

Dismissed during long-term sick leave is a textbook example: a warehouse operative with 12 years' service was dismissed after eight months off, based on a six-month-old OH report. The employee specifically asked for a fresh OH referral. The manager refused, saying "we already know what they'll say." Tribunal: unfair dismissal, £18,450 award, 0% Polkey deduction — meaning the tribunal thought there was no real chance the dismissal would have happened with a proper process.

The same pattern in healthcare worker dismissed after 948 days of sickness absence: an NHS Trust dismissed after 2½ years of absence, but relied on an 18-month-old OH report. Unfair dismissal.

2. Meaningful consultation

The employee should be told the capability process is starting, kept informed at each stage, and given a real chance to respond before any decision. "Meaningful" matters — a five-minute meeting where the employer reads out a pre-written outcome is not consultation.

This is where well-managed cases win. In long-term sickness dismissal upheld: employer followed proper process, Openreach dismissed a 13-year employee after 271 days of absence. They followed their absence management policy, held capability meetings, obtained OH reports, and consulted the employee throughout — including offers of mediation. The tribunal found the dismissal fair. Process won.

3. Reasonable adjustments

If the condition is or could be a disability under the Equality Act, the employer has a separate duty to make reasonable adjustments under section 20. This is independent of the unfair dismissal test. Failure to consider adjustments often takes a capability dismissal from "fair" to "automatically problematic."

Adjustments to consider include:

• Modified or lighter duties
• Phased return to work
• Adjusted hours or shift patterns
• Workplace equipment or ergonomic changes
• A different role within the organisation (which overlaps with redeployment, below)
• Working from home

4. Alternative employment / redeployment

Where the employee can't return to their existing role, the employer should look at whether other roles are available. Refusing to consider redeployment is one of the fastest ways to lose a capability case.

But this cuts both ways. In dismissed after refusing redeployment: a capability decision that passed the fairness test, a Housing Solutions Assistant with PTSD was offered three redeployment options and refused all of them. The tribunal found the dismissal fair — the employer had done what was required. The employee's refusal to engage with the process was decisive.

Compare that with healthcare worker dismissed after 948 days of sickness absence, where the NHS Trust failed to offer a preferential interview for a Ward Clerk role despite the employee meeting the essential criteria. Unfair.

When the absence is just too long

There comes a point where, even with good process, an employer is entitled to say "we can't wait any longer." Tribunals don't impose a fixed maximum — but the longer the absence and the less clear the return date, the easier it becomes to defend a dismissal.

Solid surface fitter dismissed after two years off sick: a fitter was off for two years following a back injury. He couldn't return to the physically demanding role and refused to consider desk-based alternatives. Capability dismissal upheld.

Dismissed after 3.5 years of sickness absence: a customer service assistant with muscular dystrophy was absent for 3½ years. Capability meetings were held, an OH report stated no return was foreseeable. Dismissal upheld.

These cases share a pattern:

• Multi-year absence
• A current medical opinion that no return is realistic
• Capability meetings held with the employee
• Reasonable adjustments and alternatives explored before dismissal

That's the template for a fair long-term sickness dismissal.

What employers commonly get wrong

Five patterns that almost guarantee an unfair dismissal finding:

1. Relying on a stale OH report. Six months is too old; 18 months is fatal.
2. Treating absence as a conduct problem. Sickness is capability, not misconduct. Mixing the two often invalidates the process.
3. Skipping the OH referral altogether because "we know the answer."
4. Refusing the employee's reasonable request for further medical evidence.
5. Not exploring adjustments and alternatives in writing before deciding to dismiss. Tribunals look for documented evidence that these were considered, not just claimed in retrospect.

The disability discrimination overlay

If your condition is long-term (12+ months) and has a substantial adverse effect on day-to-day activities, it likely qualifies as a disability. That triggers extra protections beyond unfair dismissal:

• Duty to make reasonable adjustments (s.20 Equality Act 2010)
• Discrimination arising from disability (s.15) — being treated unfavourably because of something arising from the disability, like sickness absence itself
• No two-year service requirement — discrimination protections apply from day one
• Uncapped compensation, including injury to feelings

So a long-term sickness dismissal can generate parallel unfair dismissal and disability discrimination claims — and the discrimination claim is often the bigger one, because compensation is uncapped.

What to do if it's happened to you

1. Get a copy of your file including all OH reports, meeting notes, and absence policies.
2. Check the dates of the OH evidence relied on. If it's more than a few months old, ask why no fresh report was obtained.
3. Document any adjustments or redeployment options you raised that weren't considered.
4. Use the internal appeal. Failing to appeal can reduce a tribunal award.
5. Contact ACAS for Early Conciliation within three months less one day. Strict deadline.

See real cases

Six tribunal decisions on long-term sickness dismissals — three where the employer's process was upheld as fair, three where it wasn't.

Disclaimer

This is general legal information, not legal advice. Capability and disability cases are heavily fact-specific. Contact ACAS (0300 123 1100), Citizens Advice, a trade union, or a qualified employment solicitor for advice on your situation.