The New York Stock Exchange requires all companies traded on it to utilize internal auditors. Commonly, companies do not directly hire their own internal auditors. Rather, internal auditors often are employed by an outside CPA firm, and client companies outsource their needs for internal auditors from these outside CPA firms.
a. Why don't companies hire their own internal auditors?
b. Although companies outsource their internal auditors from CPA firms, they never outsource them from their own external auditor. Why not?