If you have been absent from work for less than 7 days, you do not need a sick note from a doctor. Sick notes from doctors are only issued if you have been off work more than 7 days.
If you have been off more than 4 days, you may be entitled to Statutory Sick Pay (SSP). You will need to complete a form to “self certify” your illness if this is the case. Please visit the Government website below to obtain the form.