If you’re off work sick for 7 days or less, your employer should not ask for medical evidence that you’ve been ill. Instead, they 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. We call this self-certification.
More information is on the gov.uk website.
If your employer needs a letter from the GP for less than 7 days of sickness, this is private work. Please call 01970 613 500 option 3.