Quick answer

When do I need a fit note?

For the first 7 calendar days of sickness, employees usually self-certify and do not need a fit note. From day 8, an eligible healthcare professional can issue a fit note if health affects fitness for work. A note may say 'not fit' or 'may be fit' with adjustments.

Days 1 to 7

Tell your employer according to workplace policy and complete self-certification if requested. The employer should not send you to a GP solely for an NHS note during this period.

From day 8

Contact the team managing the condition. The fit note should cover the functional impact and expected duration, not disclose unnecessary details.

Returning to work

You can return before a fit note expires if well enough and agreed workplace safety is addressed. A separate “fit to return” note is not usually required.

Common questions

Can a fit note be backdated?
It may be backdated when the clinician can make an appropriate assessment covering the earlier period, but this is not automatic.
Who can issue a fit note?
Doctors, registered nurses, occupational therapists, pharmacists and physiotherapists can certify within their scope after an assessment.
What does 'may be fit for work' mean?
It means work may be possible with changes such as altered hours, duties, equipment or a phased return, agreed with the employer.

Sources