How Long Can a Sick Note Last? Fit Note Duration Explained

Since 2010, the old “sick note” was replaced with the fit note, formally called a Statement of Fitness for Work. The change wasn’t just cosmetic — the fit note introduced a middle option beyond simply “fit” or “unfit.” A healthcare professional can now state that you’re:

• Not fit for work, meaning you shouldn’t be working at all during the stated period, or
• May be fit for work, meaning you could return with some adjustments — reduced hours, amended duties, workplace adaptations, or a phased return.

This distinction matters for duration too, because a “may be fit” note is often shorter and paired with a review date, since the whole point is to reassess as your recovery progresses.

There’s no fixed formula, chart, or legal maximum written into how long a single fit note can cover. The length is entirely down to clinical judgement — what condition you have, how it’s affecting your ability to work, and how quickly the healthcare professional expects things to improve.

For minor illnesses or injuries — a bad flu, a stomach bug, a minor sprain, a post-operative recovery from a small procedure — a fit note is typically issued for a few days up to two weeks. The expectation is a full and fairly quick recovery, so there’s little value in certifying further ahead than that.

For more serious, chronic, or slow-recovering conditions — major surgery, significant mental health episodes, long-term musculoskeletal problems, or complex illnesses — a fit note can cover several weeks or months. In practice, GPs commonly issue notes for up to 3 months at a time during the first 6 months of a condition. After 6 months, if the condition is stable and ongoing, healthcare professionals are able to issue notes covering longer periods, since the diagnosis and prognosis are usually clearer by that point.

Stress, anxiety, depression, and other mental health conditions are treated with the same clinical judgement as physical illness — there’s no separate, shorter allowance simply because the condition isn’t physical. In fact, mental health-related fit notes are often issued with a “may be fit for work” recommendation alongside adjustments (reduced hours, a quieter workspace, flexible start times) rather than a blanket “not fit,” because a supported return can sometimes aid recovery more than prolonged absence. For a full breakdown of where you stand, see the legal implications of GP sick notes.

A common misconception is that only GPs can sign you off. That hasn’t been true since 1 July 2022. The rules were widened specifically to reduce pressure on GP appointments and cut delays for patients who mainly needed paperwork rather than a new diagnosis. Fit notes can now be issued by:

• GPs
• Registered nurses
• Pharmacists
• Occupational therapists
• Physiotherapists

Each of these professionals applies the same clinical standard — the note must reflect a genuine assessment of your fitness for work, not simply a request fulfilled on demand.

• First 7 calendar days off sick: you can self-certify your absence. No fit note or medical evidence is required — you simply tell your employer you’re unwell, usually via their standard sickness reporting process.
• From day 8 onwards: your employer can ask for a fit note from a registered healthcare professional. Some employers state this in their contract or handbook; others follow it as standard practice without it being explicitly written down, so it’s worth checking your own employer’s policy. If you’re past that point, you can get a sick note online in the UK quickly and easily.

Generally, no — not in any meaningful way. A healthcare professional can only certify fitness for work from the point they’ve actually assessed you, whether that’s an in-person appointment, a phone consultation, or (increasingly) an online assessment. They can’t retrospectively certify a period of illness they didn’t witness or assess in some form. If you were unwell for several days before you managed to get an appointment, the self-certification process — not backdating — is what covers that initial gap, provided it falls within the first 7 days.

If you’re still unwell when your current fit note runs out, there’s no automatic extension — you’ll need a new assessment and a new fit note. The practical advice here is simple: don’t wait until the expiry date to book a follow-up. Get an appointment in before the note ends, so there’s no gap between the old note expiring and the new one starting, which can otherwise create confusion with payroll or HR.

Going back to work early is much simpler. You don’t need a separate “fit to return” certificate — if you feel able to work before your note’s end date, you can simply return. Employers sometimes ask for informal confirmation, but there’s no statutory requirement for a doctor to sign you back in.

It’s worth understanding how fit note periods interact with pay, since the two run on related but separate tracks. Statutory Sick Pay (SSP) can be paid for up to 28 weeks of qualifying sickness absence. Since 6 April 2026, under the Employment Rights Act 2025, SSP is payable from the first day of qualifying absence, with the old three-day unpaid waiting period removed.

Your fit note is the medical evidence that supports an SSP claim once you’re past the 7-day self-certification period — but the note’s own length doesn’t need to match the 28-week SSP cap exactly; you might have several shorter fit notes covering one long period of absence. Not sure which type you need? See the difference between a private doctor’s note and an NHS sick note.

Occasionally, a patient feels a note is too short (and worries about the hassle of arranging a follow-up) or too long (and wants to return sooner). Both are manageable:

• If you recover faster than expected, you can simply return to work — no need to wait out the note or get it “cancelled.”
• If you need longer, book a follow-up appointment before the note expires and discuss your ongoing symptoms; a new note can be issued reflecting your current condition.
• If your employer disputes the fit note itself, they can’t simply override a healthcare professional’s medical opinion, but they can seek their own occupational health assessment, particularly for prolonged or recurring absences. This doesn’t cancel your existing fit note — it’s a separate process employers sometimes use for long-term absence management.

Fit note rules are set nationally, but how individual organisations use them varies. Some employers accept a single note covering an extended absence without any issue. Others ask for updated evidence at set intervals — particularly for recurring or long-term conditions, or where absence patterns trigger a formal review under their attendance policy. Check your contract or staff handbook, and when in doubt, ask HR directly rather than assuming your employer follows the same approach as a previous one.

• Letting a note lapse before booking a follow-up. Book ahead of the expiry date, not after — appointment availability isn’t guaranteed on short notice.
• Assuming a note can be backdated freely. Healthcare professionals can only certify from the point of assessment, with the 7-day self-certification period covering the gap before that.
• Not checking the dates carefully. A single date error on a fit note can cause payroll or HR confusion; check the note before you submit it, and query it immediately if something looks wrong.
• Ignoring the “may be fit for work” option. If your note recommends adjustments rather than full absence, it’s worth discussing these with your employer — a supported partial return is often better for both recovery and continuity than staying off entirely.

If you already know a condition is likely to need an extended period off — scheduled surgery, a known chronic condition flare-up, ongoing treatment — speaking to your GP ahead of time helps. You can plan the sequence of fit notes and follow-up appointments in advance, rather than scrambling for paperwork once you’re already off sick.