You do not require a doctor's sickness certificate for any illness lasting seven days or less. Your employer may however require you to complete a self-certification form (SC2) which is available from your employer 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).
Your employer can ask you to confirm that you've been ill.You can do this by filling in a form yourself when you return to work. This is called self-certification.
If you're sick and off work for more than seven days, your employer will probably ask for proof of your illness. Most employers ask for a fit note from your GP.
However, this will also depend on your employer's company policy on sick leave (or sickness absence). This policy should tell you how many days you can be off sick before you need to provide proof of illness or a fit note.
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.
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 return to work sooner by providing more information about the effects of your illness or injury.
For more information see the DirectGov website (where this information was sourced)
Going Back to Work
You DO NOT need a note from the doctor to enable you to return to work. Guidance from Department for Work and Pensions specifically states the following:
IMPORTANT: Your employee can go back to work at any time (including before the end of the fit note) without going back to see their doctor - even if their doctor has indicated that they need to assess them again. This will not breach your Employers Liability Compulsory Insurance, providing a suitable risk assessment has taken place if required.
Further information can be found at https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/464398/fit-note-employers-line_managers-sept-2015.pdf
Fit Notes for School Children
WE DO NOT ISSUE FIT NOTES FOR SCHOOL CHILDREN…….
GPs are not contractually obliged to provide a sick note for children who are off sick from school (ref GPC website Jan 2010). In normal circumstances when a child has been absent from school, the parent should give the child a note to take into school when he/she returns explaining the reason for absence.
Most minor illnesses are self-limiting and do not require contact with a general practitioner or a medical certificate. The GP’s role is to provide advice and treatment for childhood illnesses, when needed, to facilitate an early return to school. In cases of prolonged illness (five days or earlier if there are parental concerns), parents should telephone their GP for medical advice and will be offered telephone advice and/or an appointment if clinically necessary. Medical certification for short term illness is not appropriate and should not be requested as standard school policy. On the rare occasion medical evidence is deemed necessary by the school, due to recurrent absences related to illness, a request may be made in writing by a senior member of staff, with the parent’s informed and written consent, and a fee will be payable. GPs can only give a private medical certificate when they have documentary evidence to confirm actual illness; i.e. from the date that the child has sought medical advice. This is a ‘private’ certificate and the GP is entitled to charge a fee for this service. Retrospective certificates are not valid and should not be issued.