based in london, amba is one of the three main global accreditation bodies in business education (see triple accreditation) and styles itself as the world's impartial authority on postgraduate management education. it differs from aacsb in the us and equis in brussels as it accredits a school's portfolio of postgraduate management programmes but does not accredit undergraduate programmes. amba accredits approximately 2% of the world's business schools, and is the most international of the three organisations having accredited schools headquartered in 54 countries, compared with the 52 for aacsb and 38 for equis.