You do not require a doctor’s sickness certificate if you have been ill for seven days or less. Your employer may however require you to complete a self-certifacation form (SC2) which is available from your eompliyer or on the HMRC webiste.
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). It is up to your employer to devoid whether you are incapable of work. A medical certificate is 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 devide whether or not this eveidence is acceptable. If your employer has any doubts, they may still ask for a medical certificate from your GP.
Statement of Fitness for Work ‘Fit Note’
The ‘fit note’ was introduced on 6 April 2010. With your employer’s support, ,the note will help you to return to work sooner by providing more information about the effects of your illness or injury. For more information see the Direct Gov webiste (where this information was sourced).