In the US, state and federal securities laws require filing a legal document on the offering when stock in a private company is sold or transferred. Federal law applies in every case no matter where the private company is headquartered in or where the investor is based. In addition to that, there are state securities laws that vary by state (these are known as Blue Sky Laws — see PrivCo Private Company Knowledge Bank Terms and Definitions). With the Blue Sky Laws, each state has its own unique securities registration requirements which include registration by exemption, coordination, and private offerings. Under Blue Sky Laws, each state may also have different limitations on the number of private investors from that state who invest in the private company.