Background: I'm an accredited investor, having taken people's money who were both accredited and unaccredited and work in financial services.

There is no governing body that gives you a stamp of approval towards accreditation. It's basically only "enforced" if you get caught.

So, no, there's not practically "more to it" than checking a box. The most stringent I've seen is a notarized letter from my accountant (rare) and the least stringent I've seen is that the startup owner never asked.