Check they are a Member of a National Government Organisation

Good styles of Martial Arts and Karate should be members of a contactable government approved organisation. They should require you and your club to be paid up registered members. Why? because in most countries the government organisation is required to support the people and their communities. Which means your club has to meet a set of standards required by the Government body. Things like meeting legal, safety and training requirements, that are in your and/or your childs best interest.