You should not require a Fit note / Sick note for any illness lasting 7 days or less. Your employer may require you to complete a self-certificate (SC2) which is available from Reception, your employer, the Post Office or the DSS or access the form online.
If you need a Fit note / Sick note for illness lasting more than 7 days, you will need to see a GP and an appointment should be made as soon as possible.
If your employer insists on a Fit note / Sick note for a work absence during the first 7 days, the doctor may agree but a fee will be charged.