If you have been ill for 7 days or less you don’t need to see a Doctor. You can complete a Self Certification form yourself. However some employers insist on a Doctor’s note regardless. A Doctors note under these circumstances involves a charge.
Many employers have their own self-certification forms. If your employer doesn’t have its own form you can download this SC106082019.pdf Please print it, fill it in and hand it in to your employer. You do not need to see a Doctor.
For more information visit the Gov.UK website.