How to Apply for a County Business License. 1. Determine Whether Your Business is Located Inside or Outside the Unincorporated Areas of Contra Costa County.Contra Costa County uses the Purchasing Portal to allow vendors to easily submit and manage their company's information. To file an FBN in Contra Costa County follow these steps: 1. It is recommended for legibility that this form is completed online prior to printing. The Contra Costa Economic Partnership engages business and civic leaders to make the region a better place to live and work. Provides growing businesses with long-term, fixed-rate financing for major fixed assets, such as land and buildings. A Certified Development Company is a nonprofit corporation set up to contribute to the economic development of its community. In the event of an emergency. Republic Services is dedicated to handling your recycling and waste needs in a way that is easy, effortless, and environmentally responsible.