Most GP practices have an arrangement with a number of local pharmacies, that they will send/fax the scripts to the pharmacy (so you don't have to do the walking about) but you do have to go to the chemists to pick them up. I know of no NHS organisation where it's acceptable to have your prescriptions delivered to you by Royal Mail. It's indeed up to you where you want to cash your prescription, but I am reasonably certain that it would be considered poor clinical governance for the practice to fax your prescription to an on-line third party who then mails it to you (and you have to pay them a subscription for this service, presumably)? It's fraught with problems as far as my knowledge of primary care is concerned. The GP would have to have some sort of service level agreement with the on-line pharmacy, IMO, and all sorts of assurance about confidentiality and patient data protection.