Despite the large number of new international schools opening each year, very little innovation is evident in the market. DiMaggio and Powell (1983) use institutional isomorphism to explain the phenomenon of organisations in a field being similar and this paper investigates the extent to which accreditation contributes to that phenomenon. By reviewing the handbook, standards, and lesson observation tool of one large, global accreditor, a picture is built in this paper of the 'ideal school' that would perform well in an accreditation review. Accreditation was found to restrict how the school is managed, narrow the learning philosophy of the school, and prescribe the practices that take place in the classroom. Opportunities for limited creativity were found in teachers' design of learning activities, with the caveat that those activities must be aligned to prescribed curriculum standards.