Medical Certificate for Sick Leave: What Employees Should Know

Taking time off work due to illness is sometimes unavoidable, and knowing the correct procedures helps ensure your leave is handled smoothly and professionally. In the UK, a medical certificate—often called a “fit note”—plays a key role in verifying your absence when you're unwell. Whether you're new to the workplace or simply unsure about the rules, understanding when and how to obtain a medical certificate for sick leave is essential.

This guide explains everything employees should know, from when you need one to how to request it and what your rights are.

What Is a Medical Certificate (Fit Note)?

A medical certificate, officially known as a fit note or Statement of Fitness for Work, is a document issued by a GP, hospital doctor, or other authorised healthcare professional. It confirms that you are unfit to work due to illness or injury—or, in some cases, that you may be fit to work with certain adjustments.

Common reasons for issuing a medical certificate include:

• Flu or viral infections

• Physical injuries that limit mobility

• Mental health conditions such as anxiety or depression

• Chronic or long-term health issues that impact daily functioning

The fit note helps your employer understand the seriousness of your condition and ensures you receive statutory or contractual sick pay where eligible.

When Do You Need a Medical Certificate?

In the UK, you do not need a medical certificate for the first seven calendar days of sickness absence. During this period, you can self-certify by completing a simple form provided by your employer.

A medical certificate is required only if your sickness lasts longer than seven consecutive days (including weekends and non-working days).

However, some employers may request a certificate earlier, especially for certain high-responsibility roles. In such cases, they may ask you to pay for a private medical note, as NHS doctors are not obliged to issue notes for absences under seven days.

How to Get a Medical Certificate

Getting a medical certificate has become more flexible in recent years, with remote consultations more common than ever.

1. Contact Your GP Practice

You can request an appointment—either face-to-face, by phone, or via an online consultation. If the GP believes your condition affects your ability to work, they will issue a fit note.

2. Hospital-Issued Fit Notes

If you have been treated in hospital—for example, after surgery—the hospital doctor can issue your medical certificate without needing to see your GP.

3. Other Qualified Professionals

In some cases, healthcare professionals such as nurses, occupational therapists, and physiotherapists can issue fit notes, especially during ongoing treatment.

Employee Rights and Responsibilities

Your Rights:

• You are entitled to Statutory Sick Pay (SSP) if you meet eligibility criteria.

• Your employer must keep your medical information confidential.

• You cannot be forced to work against medical advice.

• Reasonable adjustments should be considered if the fit note recommends them.

Your Responsibilities:

• Notify your employer as soon as possible when you become ill.

• Provide a fit note promptly when required.

• Follow medical advice to support your recovery.

What If Your Employer Questions the Certificate?

Most employers accept fit notes without issue. However, if they have concerns, they may:

• Arrange an occupational health assessment

• Discuss alternative duties based on the “may be fit” advice

• Request clarification from your GP (with your consent)

Can You Work While Signed Off Sick?

Yes—but only if the fit note states you “may be fit” for work with certain adjustments. These adjustments must be agreed upon by both you and your employer.

If the fit note states “not fit for work”, you should not work until the note expires or a new note is issued.

Conclusion

A medical certificate for sick leave is a crucial document that protects both employees and employers. Knowing when you need one, how to obtain it, and what information it includes ensures you can manage sickness absence professionally and confidently. If you ever feel unsure, your GP, HR department, or occupational health service can guide you through the process.

Frequently Asked Questions

1. Do I need a medical certificate for short-term illnesses?

No. For absences of seven days or fewer, self-certification is sufficient.

2. Can I get a fit note without seeing a doctor in person?

Yes. Many GP practices offer phone or online consultations and can issue fit notes remotely.

3. Will I be charged for a medical certificate?

NHS fit notes for absences over seven days are free. Private notes for shorter absences may incur a fee.

4. What if my fit note expires but I’m still unwell?

You must request a new certificate if you remain unable to work.

5. Can my employer contact my GP?

Only with your written consent. Your medical information is confidential.