The NHS provides certain services which GPs offer and for which they are paid by the NHS.
There are many things which patients request from GPs which are not covered by this. All of these things need to be paid for as nothing can be done for free.
Grove Medical Practice Fees and Charges
Patients who are undergoing academic examinations who feel that their performance is being affected by a medical condition are advised to review the Joint Council for Qualifications (JCQ) Guide for Special Consideration and discuss the case with the examining centre and the relevant examining body as a charge will be raised for if a doctors letter is requested.