Last updated: April 2026
This guide is based on official guidance from GOV.UK, ACAS, and the British Medical Association (BMA). The information in this guide reflects current UK guidance as of 2026 and may change if government policies are updated.
If you’re off work due to illness in the UK, you may need a doctor’s sick note, officially called a fit note, but also commonly referred to as a GP sick note, Med3 certificate, or Statement of Fitness for Work. One of the most common questions employees ask is:
“How long can a doctor sign you off from work in the UK?”
The answer depends on several factors, including how long you’ve been ill, your doctor’s clinical judgement, and whether your condition is short-term or long-term.
This guide explains exactly how sick notes work in the UK, how long they can last, and when you need one.
Quick Answer: How Long Can a Doctor Give a Sick Note in the UK?
In the UK, a GP or other healthcare professional can usually issue a sick note (fit note) for up to 3 months at a time during the first 6 months of illness. After 6 months, fit notes can be issued for longer periods depending on the medical condition and clinical judgement of the issuing professional.
The exact duration of a fit note depends on your medical condition, expected recovery time, the length of your absence so far and whether your doctor believes workplace adjustments could help you return to work sooner.
Sickness Situation | Sick Note Requirement in the UK |
First 7 days of illness | You can self-certify and do not need a doctor’s sick note |
After 7 days | A doctor or healthcare professional can issue a fit note |
First 6 months of illness | Fit notes are usually issued for up to 3 months at a time |
After 6 months of illness | Doctors can issue fit notes for longer periods if medically appropriate |
What Is a Sick Note (Fit Note) in the UK?
A fit note (also called a Med3 certificate, and formally known as the Statement of Fitness for Work) is a medical certificate issued by a healthcare professional confirming that your health condition affects your ability to work.
The fit note system replaced the old “sick note” in April 2010, marking a significant shift in how sickness absence is managed. Under the previous system, doctors simply signed people off work entirely. The fit note introduced a second option: advising that a patient may be fit for work with appropriate adjustments, creating a more collaborative and return-to-work-focused approach.
It is worth noting that the term “sick note” has no legal status in UK employment law. In practice, employers and employees use it as shorthand for a fit note, which is the legally recognised form of medical evidence for sickness absence, SSP decisions, and return-to-work processes.
A fit note advises one of two things:
- Not fit for work – the healthcare professional believes you should not work at all during the specified period.
- May be fit for work – you might be able to work if your employer makes reasonable adjustments.
Most fit notes are now issued digitally through GP systems and sent directly to patients or employers, a shift accelerated since 2022.
The 7-Day Self-Certification Rule (UK Law)
According to official ACAS guidance on fit notes and proof of sickness, employees in the UK can self-certify sickness for the first 7 days.
This means:
- You simply inform your employer that you’re ill.
- No medical proof is required.
- You may need to complete a self-certification form (SC2) when returning to work.
These 7 days include weekends and bank holidays, even if you do not normally work those days. If you are ill from Monday to the following Monday inclusive, that is 8 calendar days, a fit note would be required.
If your illness lasts longer than 7 days, your employer can request a fit note from a doctor or other healthcare professional.
Some employers may ask for evidence of sickness before the 7-day threshold (for example, for the first day of absence). If this happens, the employer must cover the cost of any fee charged by the GP for providing such a note, they cannot pass this cost on to you.
Maximum Sick Note Duration a Doctor Can Issue in the UK
1. During the First 6 Months of Illness
According to the official fit note guidance from GOV.UK, for a new health condition or sickness absence:
- A doctor can issue a fit note for up to 3 months at a time.
- The doctor may schedule a review date (where applicable) to assess your condition, before issuing another note.
This allows the healthcare professional to monitor recovery and adjust the advice if necessary.
Example:
If you have surgery or a serious illness:
- Your GP might sign you off for 4–8 weeks initially
- Then extend the note if recovery takes longer.
In practice, the duration of a fit note is determined by the healthcare professional’s clinical judgement. Shorter notes (for example, 2 to 4 weeks) are common for acute conditions with a predictable recovery, while longer notes are more typical for conditions such as depression, anxiety, or musculoskeletal disorders, where recovery is less linear.
2. After 6 Months of Sickness
Once your condition has lasted more than 6 months, doctors have more flexibility.
They may issue a fit note:
- For longer periods
- Sometimes indefinitely, depending on the condition
- With periodic reviews to assess recovery
This often applies to long-term illnesses or disabilities.
Who Can Issue a Sick Note in the UK?
Many people think only GPs can sign someone off work, but this is no longer the case. Since 2022, several healthcare professionals, not only GPs, can issue fit notes in the UK.
These include:
- GP doctors
- Hospital doctors
- Nurses (including nurse practitioners and advanced nurse practitioners)
- Physiotherapists
- Occupational therapists
- Pharmacists
The professional issuing the note must be involved in your care or treatment.
This change is particularly relevant for patients receiving treatment in hospital settings, community clinics, or through specialist services, as it removes the need for a separate GP appointment solely to obtain a fit note.
What a UK Fit Note Can Say About Your Ability to Work
A UK fit note usually states one of two things:
1. Not Fit for Work
This means the doctor believes you should not work at all during the specified period.
2. May Be Fit for Work
This means you might be able to work if your employer makes adjustments, such as:
- Reduced hours
- Working from home
- Modified duties
- Gradual return to work
- Workplace adaptations
Employers are not legally required to follow the advice, but it is usually used to guide discussions about workplace adjustments. Most HR professionals and employment lawyers recommend treating fit note advice seriously, as ignoring it without good reason could complicate any future employment dispute.
If your employer cannot accommodate the suggested adjustments, the note defaults in effect to treating you as not fit for work.
Can a Sick Note Be Extended?
Yes. If you are still unwell when your current fit note expires, you can request an extension.
Doctors may:
- Issue another fit note after reassessment
- Extend the duration without a full appointment (sometimes via phone consultation)
You should contact your GP practice before your current fit note expires to avoid any gap in your documentation.
Can GPs Back Date a Fit Note in the UK?
According to the British Medical Association (BMA), GPs can backdate a fit note when appropriate. In some cases, the dates on the fit note may need to start before the date the note is issued.
If the fit note is based on a medical assessment carried out earlier, the doctor should record the actual date of that assessment in the “date of assessment” field.
If the patient’s condition has been affecting their ability to work for some time but no fit note was issued earlier, the GP should include an estimated start date in the “this will be the case from” section to indicate when the condition likely began affecting the patient’s function.
This is particularly relevant if you delayed seeking medical attention, or if your condition worsened gradually before you realised it warranted formal documentation.
Can You Return to Work Before Your Sick Note Ends?
Yes.
If you recover earlier than expected:
- You do not need a doctor’s note confirming you’re fit again.
- Simply inform your employer that you are ready to return.
However, some workplaces may require a return-to-work meeting.
Do You Have to Pay for a Sick Note in the UK?
Usually no, if:
- You have been off work more than 7 days
- The fit note is issued through the NHS
However, you may have to pay a fee if:
- Your employer asks for a doctor’s note for less than 7 days (in this case, the cost should be covered by the employer)
- You request a private medical certificate.
Sick Notes and Statutory Sick Pay (SSP)
A fit note may be required if you want to claim Statutory Sick Pay (SSP).
Employers use the document as medical evidence of incapacity to work.
If a healthcare professional confirms that you are not fit for work, this can be used as evidence that you qualify for Statutory Sick Pay (SSP).
Important: From 6 April 2026, changes introduced by the Employment Rights Act 2025 have made Statutory Sick Pay easier to access and available for workers across the UK.
These key changes include:
- Statutory Sick Pay (SSP) is now available to all eligible employees, with the previous minimum earnings threshold removed.
- Payments begin from the first day of sickness absence, with the three-day waiting period no longer applying.
- The amount you receive is calculated as 80% of your average weekly earnings or the standard weekly rate—whichever is lower.
If your employer does not provide SSP when it should apply, you can raise the issue with the Fair work Agency. You may also consider seeking advice or support from a trade union or ACAS (Advisory, Conciliation and Arbitration Service) in these situations.
Read our detailed guide on SSP changes 2026 UK.
Common Reasons Doctors Issue Sick Notes
Some of the most common medical reasons include:
- Mental health conditions (stress, anxiety, depression) – the leading cause of long-term sickness absence in the UK
- Musculoskeletal injuries (back pain, joint issues)
- Surgery recovery
- Serious infections or illness
- Pregnancy-related complications
- Chronic conditions
The length of the note often depends on recovery time and workplace demands.
Read our detailed guide on common reasons for sick leave in the UK.
Key Takeaways
- You can self-certify sickness for the first 7 days in the UK.
- After that, you need a fit note from a healthcare professional.
- For the first 6 months of illness, a doctor can issue a sick note for up to 3 months at a time.
- After 6 months, notes can be issued for longer or indefinite periods, depending on the condition.
- Fit notes can include advice about returning to work with adjustments.
Understanding how long a doctor can issue a sick note in the UK helps employees and employers manage sickness absence correctly. Fit notes provide medical evidence of illness and can support workplace adjustments to help people return to work safely.
Sources
- GOV.UK – Fit Note Guidance for Patients and Employees
- ACAS – Fit Notes and Proof of Sickness
- British Medical Association – Fit Note Guidance
Frequently Asked Questions (FAQs)
Yes. A doctor can refuse to issue a fit note if they believe your health condition does not prevent you from working. Fit notes are only issued when a healthcare professional determines that your illness affects your ability to do your job.
Yes. Many GP practices now provide online fit notes after phone or video consultations.
They usually cannot challenge the medical opinion directly, but they may request occupational health assessments.
Yes. Doctors can backdate a fit note if you were already ill and unable to work earlier.
Yes. Many GP practices can issue a fit note after a phone, video, or online consultation. In some cases, other healthcare professionals such as nurses, physiotherapists, occupational therapists, or pharmacists can also issue fit notes if they are responsible for your care.
Learn more in our guide on whether an employer can override a doctor’s sick cert.
No. Employers cannot contact your doctor without your permission due to medical confidentiality rules. If more information is needed, they may ask for your written consent for a medical report or occupational health assessment.
Disclaimer: This article is for general informational purposes only and does not constitute medical or legal advice.
