Your GP will issue this document if you are not fit to work or are able to return under certain circumstances. The fit note may include advice from your GP on how you may be able to return to work.
Self certification is valid for the first 7 calendar days you are absent from work. Self certification forms are either available from your employer or at reception. If your employer is requesting a note for any absence shorter than 7 days this would need to be a private sick note, for which there is a charge. Information explaining why we do not issue notes for under 7 days absence is available from reception.
You can find more details online at www.dwp.gov.uk/fitnote.