My practice requires people to call when the practice opens (08:30) in order to book an appointment. Of course, the lines are busy but you have to queue, if you hang up then tough. They don't entertain appointment calls at any other time of day unless it's a GP (not a nurse or AHP) who books a follow-up themselves during a consultation. There is no online service, presumably because you have to pass the receptionnist's vetting process first. This has been the system for about four or five years now. I'm wondering how many other GP surgeries do this.