Request a Medical Certification Note
Medical Certification Note (Fit Notes)
All patients are expected to self-certificate for the first seven days of an illness.
This is UK NHS Guidance and all employers should accept this.
Formal Medical Certification - Fit Note
If your period of sickness continues and you need a formal sick note for your employer
Then you will need to be examined by a GP for a first 'Fitness to Work' note to be issued.
If the illness continues further and you need another note this can in many situations be renewed via a telephone appointment
Form SC2 [medical certification] - Link to HMRC Self Certification Form