A Fictitious Business Name shall be filed within 40 days of first transacting business. Once registered, it is effective for 5 years.Official Website for Riverside County California Clerk Recorders Office. If you are planning to conduct business in the City of Riverside you must obtain a City of Riverside business license, also referred to as a business tax. Official Website for Riverside County California Clerk Recorders Office. If you are planning to conduct business in the City of Riverside you must obtain a City of Riverside business license, also referred to as a business tax. The only approved online food handler training for all Riverside County, California, food workers. Train, test, and print your Riverside Food Handlers Card!