A series LLC is a form of limited liability company that provides liability protection to multiple "series". Essentially, it's a master LLC with separate divisions, each protected and operating independently. As an entity, the series LLC is geared towards businesses where investors own multiple companies, with each series being protected from the debts and obligations of the other series. Currently, only several states support this option, including Delaware, Illinois, Iowa, Nevada, Oklahoma, Puerto Rico, Tennessee, Texas, and Utah.
Unlike in many other Western countries, Canadian businesses generally only have one form of incorporation available. Unlimited liability corporations can be formed in Alberta "AULC", British Columbia "BCULC" and Nova Scotia "NSULC". The aforementioned unlimited liability corporations are generally not used as operating business structures, but are instead used to create favorable tax positions for either Americans investing in Canada or vice versa. For U.S. tax purposes the ULC is classified as a disregarded entity.