Does having the AAT qualifications enable you to credibly call yourself an accountant or is it widely accepted as more of an assistant / bookkeeping qualification ?
It probably falls somewhere between the two but in practice most people who hold the AAT qualification work as bookkeepers, although the AAT syllabus does go beyond just bookkeeping.
At best, you could probably call yourself a part qualified accountant. Of course, no formal qualifications are at present required to practice as an accountant so anyone can call themselves an accountant and in fact some of the best accountants around have no or few formal qualifications, instead being qualified by experience. But to get back to your question, I do not think somebody who only holds AAT could credibly call themselves a 'qualified' accountant.