Treaty Trader (E-1 visa) and Treaty Investor (E-2 visa) visas are issued to citizens of countries that have signed treaties of commerce and navigation with the United States. They are issued to individuals working in businesses engaged in substantial international trade or to investors (and their employees) who have made a 'substantial investment' in a business in the United States. The variant visa issued only to citizens of Australia is the E-3 visa (E-3D visa is issued to spouse or child of E-3 visa holder and E-3R to a returning E-3 holder).