Sick Note vs Fit Note: Is There a Difference?
A sick note and a fit note are the same document. "Fit note" is the official UK name, introduced in April 2010 to replace the older "sick note" system. The formal title is the Statement of Fitness for Work (Med3 form). Most people still say "sick note" in everyday conversation, but the legal document your doctor issues is always a fit note.
The name change was not cosmetic. It reflected a shift in how UK medical evidence works. Under the old sick note system, a doctor could only declare you unfit for work. The fit note added a second option: you may be fit for work if your employer makes certain adjustments, such as reduced hours, lighter duties, or a phased return. This means the document now actively supports recovery rather than simply recording absence.
Whether you search for "sick note" or "fit note," you will receive the same medical certificate from the same healthcare professionals, governed by the same employment law. The distinction matters only in understanding what the document can say about your ability to work.
Sick Note vs Fit Note: Side-by-Side Comparison
| Feature | Old Sick Note (pre-2010) | Modern Fit Note (2010 onwards) |
|---|---|---|
| Official name | Medical Statement (Med3) | Statement of Fitness for Work (Med3) |
| What it can say | Unfit for work only | "Not fit for work" or "May be fit for work" with adjustments |
| Workplace adjustments | Not included | Doctor can recommend phased return, amended duties, altered hours, or workplace adaptations |
| Who can issue it | GPs and hospital doctors | GPs, hospital doctors, registered nurses, occupational therapists, pharmacists, physiotherapists (expanded from July 2022) |
| Format | Paper only | Paper or digital (digital became standard from April 2022) |
| Used for SSP | Yes | Yes |
| Used for ESA/Universal Credit | Yes (historically) | Yes (NHS Med3 only, not private certificates) |
| Still in use | No, replaced in 2010 | Yes, current UK standard |
The table above summarises the practical differences. The core change is that the fit note gives doctors a way to support a managed return to work, rather than defaulting to complete absence. This benefits employees who could work with reasonable adjustments, and employers who want to retain staff through illness rather than lose them to prolonged absence.
The Two Outcomes on a Fit Note
Every fit note contains one of two assessments. Understanding which one applies to you affects how your employer should respond.
"Not Fit for Work"
The doctor's clinical opinion is that you should not work at all during the period covered by the fit note. Your employer cannot require you to return before the end date. You do not need a separate "return to work" certificate if you recover before the fit note expires. You can simply go back when you feel ready.
"May Be Fit for Work"
The doctor believes you could return to work if your employer makes specific adjustments. These might include amended duties, altered hours, a phased return, or workplace adaptations. Your employer should discuss these with you. If the adjustments cannot be made, you are treated as not fit for work for the duration of the note. According to GOV.UK, the employee must be treated as not fit for work if no agreement on changes is reached.
This two-outcome structure is the defining feature that separates the modern fit note from the old sick note. It gives employees and employers a framework for having a constructive conversation about return-to-work options, guided by medical advice.
Who Can Issue a Fit Note in the UK?
The range of healthcare professionals authorised to issue fit notes expanded significantly in July 2022. Before that date, only doctors (GPs and hospital doctors) could sign fit notes. The change was introduced to reduce pressure on GP appointments and improve access for patients.
The following healthcare professionals can now issue a fit note:
💉 Doctors
GPs and hospital doctors. This includes both NHS and private GMC-registered doctors.
🩺 Nurses
Registered nurses, including practice nurses and specialist nurses.
🧹 Occupational Therapists
Particularly relevant for workplace-related conditions and return-to-work planning.
💊 Pharmacists & Physiotherapists
Added in the July 2022 expansion to improve patient access.
A fit note from any of these professionals carries the same legal weight. Your employer cannot reject a fit note because it was issued by a nurse rather than a doctor.
When Do You Need a Fit Note?
The 7-Day Self-Certification Rule
For the first 7 calendar days of illness (including weekends and bank holidays), you do not need a fit note. You can self-certify your absence. Your employer may ask you to complete a self-certification form (SC2) when you return. A fit note is only required from the 8th calendar day of absence onwards. This rule is set out in GOV.UK guidance on taking sick leave.
| Absence Length | Documentation Required | Who Provides It |
|---|---|---|
| Days 1 to 7 | Self-certification (SC2 form or employer's own form) | The employee |
| Day 8 onwards | Fit note (Statement of Fitness for Work) | GP, hospital doctor, nurse, OT, pharmacist, or physiotherapist |
Some employers request a fit note before day 8 as a matter of company policy, but they cannot legally require one during the self-certification period for Statutory Sick Pay purposes.
Private Medical Certificate vs NHS Fit Note
There is a practical distinction between an NHS fit note and a private medical certificate that matters for specific purposes. Both are issued by GMC-registered doctors following a clinical assessment. Both are accepted by UK employers for absence documentation and Statutory Sick Pay. The difference lies in government benefit claims.
| Feature | NHS Fit Note (Med3) | Private Medical Certificate |
|---|---|---|
| Issued by | NHS GP or hospital doctor | Private GMC-registered doctor (including online services) |
| Accepted by employers | Yes | Yes |
| Valid for SSP | Yes | Yes |
| Valid for ESA / Universal Credit | Yes | No |
| Cost | Free via NHS | Paid (typically issued same day) |
| Waiting time | Depends on GP availability (often 1 to 3 weeks) | Usually same day or next morning |
⚠️ Important: Med3 Limitation
Private medical certificates are not NHS Med3 Fit Notes. They cannot be used for government benefit claims including Employment and Support Allowance (ESA) or Universal Credit. If you need documentation for benefit claims, you must obtain an NHS Med3 from your registered GP. Private certificates are valid for employer absence records and Statutory Sick Pay only.
For most employees, a private medical certificate serves the same purpose as an NHS fit note. It confirms your condition to your employer, supports your absence record, and satisfies the documentation requirements for Statutory Sick Pay. The private route is particularly useful when GP appointments are not available within the timeframe your employer requires.
If a doctor cannot issue a certificate on clinical grounds, you receive a full refund.
Fit Notes and Statutory Sick Pay
A fit note is the primary piece of medical evidence used by employers to process Statutory Sick Pay (SSP). Under the current rules (updated April 2026), SSP is payable from day one of absence. The previous three waiting days have been abolished, and the lower earnings limit has been removed, meaning part-time workers and those on zero-hours contracts now qualify.
The current SSP rate is £123.25 per week, or 80% of average weekly earnings, whichever is lower. Many employers offer contractual sick pay above this statutory minimum. Your fit note (or private medical certificate for absences beyond 7 days) provides the documentation your employer needs to process your SSP claim.
For a full explanation of SSP rules and employer obligations, see Sick Note for Work.
Common Questions About Sick Notes and Fit Notes
Is a sick note the same as a fit note?
Yes. "Sick note" and "fit note" refer to the same document. The UK government renamed the sick note to the "Statement of Fitness for Work" (fit note) in April 2010. The change reflected a shift from simply certifying absence to assessing whether an employee could return to work with adjustments. Both terms are widely understood by employers, HR departments, and payroll teams.
What replaced the old sick note?
The fit note replaced the old-style sick note in April 2010. The key change was adding a "may be fit for work" option alongside the existing "not fit for work" assessment. This allows doctors to recommend workplace adjustments such as amended duties, altered hours, or a phased return, rather than defaulting to complete absence.
Can I still ask my doctor for a sick note?
Yes. Your doctor will understand exactly what you mean. In practice, most people still say "sick note" and every GP, nurse, and pharmacist in the UK knows this refers to a fit note. The document you receive will be titled "Statement of Fitness for Work" regardless of what you call it when requesting it.
Who can issue a fit note in the UK?
GPs, hospital doctors, registered nurses, occupational therapists, pharmacists, and physiotherapists can all issue fit notes. This expanded list took effect in July 2022 under changes to the Social Security (Medical Evidence) Regulations. Previously, only doctors could sign fit notes. Private GMC-registered doctors can also issue medical certificates that serve the same employer-facing purpose.
Do I need a fit note for 1 week off work?
No. For absences of 7 calendar days or fewer (including weekends and bank holidays), you can self-certify your illness. Your employer may ask you to complete a self-certification form when you return, but they cannot require a fit note during this period. A fit note is only legally required from the 8th calendar day of absence.
Can I get a fit note online?
Yes. Private online medical services employ GMC-registered UK doctors who can assess your condition remotely and issue a medical certificate the same day. Digital fit notes have been standard across UK healthcare since April 2022, so the online format carries the same legal weight as a paper document. Online certificates are accepted by employers for absence records and Statutory Sick Pay purposes.
Can my employer reject a fit note?
An employer cannot override the medical opinion on a fit note. If your fit note says "not fit for work," your employer must accept that assessment for the covered period. If it says "may be fit for work" with adjustments, your employer should discuss those adjustments with you. If the employer cannot accommodate the recommended adjustments, you must be treated as not fit for work. This is set out in GOV.UK guidance on fit notes for employers.
Can I go back to work before my fit note expires?
Yes. You do not need a separate "return to work" certificate. If you feel well enough to return before the end date on your fit note, you can simply go back. Your employer may ask you to confirm in writing that you feel fit to return, but they cannot require another medical document to authorise your early return.
Is a private sick note valid for my employer?
Yes. A private medical certificate issued by a GMC-registered doctor is accepted by UK employers for absence documentation and Statutory Sick Pay. The distinction is that private certificates are not NHS Med3 forms, so they cannot be used for government benefit claims such as Employment and Support Allowance or Universal Credit. For workplace purposes, a private certificate functions identically to an NHS fit note.
What does a fit note look like?
A fit note is a standardised form titled "Statement of Fitness for Work." It includes the date of assessment, the condition affecting your fitness for work, the doctor's assessment ("not fit for work" or "may be fit for work"), any recommended workplace adjustments, the period the note covers, and the issuing clinician's details. Digital fit notes are sent electronically and contain the same information as paper versions.
Sources and Further Reading
- GOV.UK: Taking Sick Leave
- GOV.UK: Fit Note Guide for Patients and Employees
- GOV.UK: Statutory Sick Pay
- ACAS: Absence from Work
- Social Security (Medical Evidence) and Statutory Sick Pay (Medical Evidence) (Amendment) Regulations 2022