User blog comment:Martialmaniac/Why the Hunters Association?/@comment-10528819-20151205110311/@comment-5780397-20151206151957

So you're saying the HA is basically the evolution of a school like the Shingen-ryu kung fu? Since it appears to have been founded pretty far in the past, I think it was really born just as a gather of specialists or geniuses who knew Nen.

Nevertheless, I think there is only one for multiple reasons: first, during the exam, you have to be skilled enough to reach the location, so moving from any part of the world to that place is part of your tasks. Since the location changes every year, it shouldn't be too unfair. As for the HQ, Hunters basically have unlimited freedom of movement and large funds, so they should be able to reach it and contact each other at any time (think of Cluck's ability), but most importantly, they are supposed to be travelling around the world for most of the time. Aside from the election, there shouldn't be a reason why Hunters need to be summoned. Anyway, the HQ is the place where the chairman, vice chairman and counsellors gather, it's not impossible that there are minor buildings of the association in other countries, but since it is an organization that relies entirely on one's skills, they should not be necessary.