Who exactly is an Executive Officer under Reg O?

In large part, it is whoever your bank says it is. Reg O defines an Executive Officer as an individual who participates or has the authority to participate (other than as a director) in major policy making functions of the bank, irrespective of title or compensation. Reg O adds some additional guidelines here, but the bottom line is that you really need to spell out who this actually is in your shop. Banks sometimes issue vanity titles to make people feel important even if they don’t have real authority (come on, we all know that happens), so it is important to actually designate who the institution considers to be an “Executive Officer” for Reg O purposes. You don’t want examiners to be making the determination for you.