A doctor's sick note is not required for absences of less than 6 days. For absences lasting less than 6 days a self–certification note otherwise known as an SC1 form should be completed and returned to your employer. These forms are available from the surgery or the post office.
Private sick notes may be issued at your request by your doctor for absences less than 6 days (for which a small fee is payable). Please remember, however, that legally you are not required to provide a sick note other than a self–certification note for absences less than 6 consecutive days if symptoms persist.