It is not necessary for your GP to issue a certificate for the first 7 days of your illness. After 3 days of absence ask your employer for a self-certification form, which allows you to self certify for up to 7 days. If you are ill for more than 6 days you will need to see the GP for a certificate.

If you require a sick note from your GP for insurance purposes you will need a private note and this will incur a charge.