Originally Posted by biggestbopper

The reason this sort of thing is in there is because business cards used for business are not protected by the Fair Credit Billing Act.

Probably not going to be problem for getting miles--could be a problem if there is a billing error on the account.

Personally, good rule is to never use a biz card unless you are working on a big bonus. At all other times use a personal card. The FCBA is your friend.