How vampires used to manage to maintain their identity as human?

So Cullens had managed to maintain their identity as a human being in the real world. Well how did that really happened?

Knowing the facts that one will always get into a school/college if and only if he would be having some of his past records like past year results, birth certificate etc. Also Carlisle was a doctor by his profession which would be needing him some kind of degree and graduation certificate to get involve in the profession.

So how is all this happening?