In the state of California, the government exemption for sales and use tax does not apply to federal contractors purchasing materials for the job because they are not considered agents of the government. This would also include construction contractors. However, government contractors are considered retailers purchasing machinery and/or equipment to fulfill a government contract. A resale certificate can be issued for purchases but the title of the property must pass over to the government before any piece of equipment or material is used by the contractor. (Tax Facts Publication No. 102, California State Board of Equalization, September 2002.)