What Is a Fit Note? A Complete UK Guide

A fit note is the document your doctor gives you when you need time off work due to illness or injury. Officially called a Statement of Fitness for Work, it replaced the old-style sick note in 2010 and changed how medical evidence works in UK employment. This complete guide explains what a fit note is, who can issue one, how long they last, and what your options are if you cannot get one from your GP.

How Fit Notes Work

When a doctor assesses you, they will decide one of two things:

• You are not fit for work - you should stay off work entirely for the recommended period.
• You may be fit for work with adjustments - you could return to work if your employer makes certain changes, such as reduced hours, amended duties, or a phased return.

This is the key difference from the old sick note system. Rather than simply declaring you "sick," the fit note encourages a conversation between you and your employer about whether any adjustments could help you return to work sooner.

If your employer cannot accommodate the recommended adjustments, you are treated as unfit for work for the duration of the note.

Who Can Issue a Fit Note?

Since July 2022, a wider range of healthcare professionals can issue fit notes. Previously, only doctors could sign them. Now the following professionals are authorised:

• Doctors (GPs, hospital doctors, and private GMC-registered doctors)
• Nurses
• Occupational therapists
• Pharmacists
• Physiotherapists

This includes private doctors. A medical certificate from a GMC-registered private doctor - like those at DoctorCert - is a legitimate alternative to an NHS fit note for most purposes.

When Do You Need a Fit Note?

You do not need a fit note for short absences. The rules are:

• Days 1-7: Self-certification is sufficient. You can fill in a self-certification form (SC2) when you return to work, or write a simple statement.
• Day 8 onwards: Your employer can legally ask for a fit note. This is also the point at which you must provide one if you are claiming Statutory Sick Pay (SSP).

Some employers request medical evidence earlier - from day 1 or day 3. This is allowed under company policy for contractual sick pay, but for SSP purposes, a fit note is only required from day 8.

What Information Does a Fit Note Contain?

A standard fit note includes:

• Your name
• The date of the assessment
• The diagnosis or condition causing your absence
• Whether you are "not fit for work" or "may be fit for work" with adjustments
• The recommended period of absence
• Any suggested workplace adjustments
• The doctor's signature and details

Your employer does not have the right to know your full medical history. The fit note gives them only what they need to manage your absence.

How Long Does a Fit Note Last?

There is no fixed duration. A fit note can cover anything from a few days to several months. The doctor decides the appropriate length based on your condition. For a first fit note, GPs often issue them for up to 4 weeks. If you need longer, you will need a follow-up assessment for a new note.

You can go back to work before your fit note expires - you do not need a separate "return to work" note.

If your recovery moves faster than expected, read our guide to returning to work before a sick note ends for the practical rules on going back early.

What If You Cannot Get a GP Appointment?

This is one of the most common frustrations in the UK. You are unwell, your employer is asking for documentation, but your GP has no appointments for a week or more. In this situation, private online services offer a practical solution.

DoctorCert allows you to request a medical certificate from a GMC-registered doctor entirely online. You complete a secure form describing your condition, a doctor reviews your case, and your certificate is emailed to you - often on the same day. The cost is a flat £29, with a full refund if the doctor cannot issue a certificate.

If a delayed appointment means you are trying to document earlier absence dates, see our guide to backdated sick notes in the UK.

Frequently Asked Questions

Can my employer reject a fit note?

Your employer must accept a fit note from a registered medical practitioner. They cannot override the doctor's clinical judgement. However, if the fit note says you "may be fit" with adjustments and they can provide those adjustments, they can expect you to return.

Can I get a fit note for stress?

Yes. Work-related stress, anxiety, depression, and burnout are all valid reasons for a fit note. Mental health conditions account for a significant proportion of workplace absences in the UK, and doctors treat them with the same seriousness as physical conditions.

Can I get a backdated fit note?

Doctors can issue a fit note covering a period in the past if they believe you were genuinely unwell during that time. Private doctors, including those at DoctorCert, can typically cover up to 14 days in the past.

Do I need a fit note to return to work?

No. You can return to work at any point during your fit note if you feel well enough. You do not need a separate clearance note from your doctor.

Summary

A fit note is the UK's standard medical document for workplace absence. You need one from day 8 of illness, and it can be issued by GPs, hospital doctors, or private GMC-registered doctors. If GP appointments are unavailable, private services like DoctorCert provide a same-day alternative.

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Need a medical certificate?

If you need signed medical evidence for work, study, or administrative purposes, you can request a private medical certificate online from a GMC-registered doctor, usually issued within 2 hours during business hours. See the one-off pricing and how private medical certificates work before you start.