Yes there is. Osteopaths by law can only call themselves an Osteopath if they are registered with the General Osteopathic Council (GOsC).
To be registered with GOsC every osteopath has to have confirmation by their university that that graduate osteopath has met the criteria and has passed their final clinical competance exams.
Without this, and without valid insurance, the GOsC will not accept osteopaths into their register.
You as a prospective patient can find out information about your osteopath by going to the GOsC website and searching the register. This will show you the year they graduated and whether they are registered and practicing or not, and it will also show whether they are currently being investigated for anything.
The General Osteopathic Council is there to protect you the patient and answer any questions or complaints you may have against any osteopathic practitioner.
We would suggest that you do check their register to ensure they are registered before you book an appointment with them. We have come across people claiming to be osteopaths but who are actually not registered (not here in our clinic though) where we have had to report them.
The General Osteopathic Council website is www.osteopathy.org.uk