Tax Factory Inc. Tax Factory was founded in 1975. This privately owned company has continued to prosper in the Vacaville area for over 30 years. When our company first opened its doors, the city of Vacaville was still considered a small town. However since the company's conception to date, Vacaville has become one of the fastest growing communities in the state. Tax Factory has grown as a company to suit the needs of an ever increasing population and continues to be committed to serving our clients. We offer a wide range of services that also extend outside the city as well as the state as our employees are required to keep current of all tax laws and changes that affect our clients where ever they may go.