Yeah. I was wondering why, instead of checking retirement plans or income taxes, why doesn't the employer just ask the employee? If you cannot trust you employee to be honest with you, then there's already a problem. In addition, you should make clear to your employees what your expectations are. If you make it clear that moonlighting is not allowed, it is not allowed. Anyone who has a problem with that can talk to the company and discuss whether they have a legitimate reason for being an exception case. Honesty is the best policy!