This is a funny one. I have heard of many people having these types of issues using a USAA code. Some say it is for business of the employees while others say it is for members only. Well, the one I saw online matched the one I saw when trying to book a car directly through USAA, I am an actual member. I have also heard of people being asked for membership ID, I never did have one of those but I would think my USAA bank card should suffice.