For the first seven days no fitness for work certificate is required for any illness. Your employer may however require you to complete a self-certification form (SC2) which is available from your employer, local job centre or on the HMRC website.
Evidence that you are sick
If you are sick for more than seven days, your employer can ask you to give them some form of medical evidence to support payment of SSP (statutory sick pay). You will therefore need to make an appointment to see a Doctor.
It is up to your employer to decide whether you are incapable of work. A medical certificate, now called a ‘Statement of Fitness for Work’ (see below) from your doctor is strong evidence that you are sick and would normally be accepted, unless there is evidence to prove otherwise.
You could also provide evidence from someone who is not a medical practitioner, e.g. a dentist. Your employer will decide whether or not this evidence is acceptable. If your employer has any doubts, they may still ask for a medical certificate from your GP.
Going back to work
You should go back to work as soon as you feel able to and with your employer’s agreement – this may
be before your fit note runs out. You do not need to go back to see your doctor before going back to
work. Your doctor cannot give you a fit note stating that you are ‘fit for work’.
For more information see the DirectGov website (where this information was sourced)