If employees are off work for 7 days or less, they do not need to give their employer a fit note or other proof of sickness from a healthcare professional.  When they return to work, their employer can ask them to confirm they’ve been off sick. This is called ‘self-certification’. The employer and employee will agree on how the employee should do this. They might need to fill in a form or send details of their sick leave by email.

https://www.gov.uk/taking-sick-leave 

If you have been ill for more than 7 days you may need a doctor’s certificate. These certificates are called ‘Fitness To Work’ Certificates. The doctor may call/contact you or arrange for an appointment. If you have already been seen by your doctor about this illness your certificate will be sent to you within a week, or you will need to have a consultation to discuss further.  You can request a fit note/doctor's certificate through our online system here, or alternatively call reception to discuss.