non-accredited school
Refers to a school that has not received official accreditation from the relevant educational authorities. Often used in contexts discussing alternative or unregulated educational institutions.
That non-accredited school offers its own curriculum.
認可校 means an accredited or officially recognized school, the opposite of 無認可校.
Compound of 無 (mu, 'without') + 認可 (ninka, 'accreditation') + 校 (kō, 'school').