Smog or emission check facilities are common in states with tight air pollution controls. States like California and New York allow facilities that are not auto repair businesses to perform emission tests and issue official reports required for vehicle licensing and renewal. Emissions testing shops must hold special state licenses and in some cases, licensing agreements to operate their computer systems.
Being one of California and the nation’s major cities means San Diego is home to many businesses. However, the city’s licensing systems are fairly decentralized requiring business owners to apply to numerous departments including the city treasurer, planning and development and the police. Additionally, licenses from San Diego County, the state and sometimes the federal government are required in certain industries. San Diego's major industries include defense, international trade, shipping, tourism, manufacturing, research and real estate. The city's close proximity to Mexico and large natural harbor make it a gateway to commerce with Asia and Latin America.