A Fictitious Business Name shall be filed within 40 days of first transacting business. Once registered, it is effective for 5 years.If you'll be operating your business from your home residence, you'll need a Home Occupancy Permit from the Planning Department. Fictitious Business Names. Contact the County Clerk to file a fictitious business name, at (951) 486-7000 or find the nearest office location. Para más información llamar al (951) 826-5465. Use the SEARCH BAR above to find your form more quickly. Just type in the name of the form. Check with the Planning Department in order to determine if your business can be legally established at your location. This guide will walk you through the entire process, step-by-step, for forming your California LLC.