without licence to practice (as a doctor, dentist, veterinary surgeon or pharmacist)
Good morning Sibylle,
"Bestallung" in the old(er) term for "Approbation", to be without "Bestallung" is therefore to be "without admission to medical practice" which, in Germany, is reserved to the a/m professions and does not include Heilpraktiker. (Heilpraktikergesetz => Ausübung der Heilkunde ohne Approbation als Arzt).
Neither appointment nor registration is the correct translation for "ohne Bestallung", as the Heilpraktiker requires an "Erlaubnis" by the competent authorities (Gesundheitsamt) in any case, which corresponds to a registration. Appointment, however, is not required.
I'm assuming your are doing a translation for NZQA or similar and would therefore suggest leaving the German term in the text and adding an explanation in English. Apparently, they have huge records to check what a foreign professional title actually entails to verify this.
Greetings from one adopted Kiwi to another!