If you are off work for 7 days or less, you do not need to give your employer a fit note or other proof of sickness from a medical professional.
Your employer may however require you to complete a self-certification form (SC2) which is available from your employer or you can download it from the HMRC website.
You must give your employer a doctor’s ‘fit note’ (sometimes called a ‘sick note’) if you’ve been ill for more than 7 days in a row and have taken sick leave. This includes non-working days, such as weekends and bank holidays.
Taken sick leave for more than 7 days in a row? Request your sick/fit note here.