Castellon
Professional
Services PC
(CPS)
About Us
Castellon Professional Services PC was founded in 2000 and has been serving individuals, partnerships, closely held corporations, and multinational publicly traded corporations for over 20 years.
They believe that CPAs are there to help and support their clients. To this end, they have developed an inclusive system designed to enhance clients' financial literacy, allowing them to learn and make informed decisions about their finances.
Meet Frank Mario Castellon, an accomplished tax consultant, CPA, and founder of Castellon Professional Services PC. Frank, along with his companion Kimmy, the tax doggie, have been tackling complex tax issues for over 20 years. Mario's extensive experience includes consulting outside of his own firm, working with the Big Four accounting firms, and assisting numerous individuals and senior managers in making strategic tax decisions while ensuring compliance with tax regulations. Above all, Mario is driven by a deep passion for helping people, viewing it as his life mission to support clients in achieving their financial goals and navigating the complexities of their financial landscape.
Frank Mario Castellon
CPA, CGMA, MST
Mission Statement
Revolutionizing tax accounting through a transformative client experience—focusing on your goals and providing personalized financial education for a bigger and brighter financial future.
Darryl brings 20+ years of corporate work experience in various areas including financial analysis and project management. Companies worked for include AT&T, Hewlett Packard, and Kaiser as well as experience with various business start up’s, and non-profits. The past 9 years have focused primarily as a tax professional working as Tax Manager under Ferguson & Co. CPA’s, and in 2024 he officially became an Enrolled Agent (EA). Over the years, he’s become adept at building relationships, critical thinking, and problem solving.
Darryl Dunn
MBA, EA
Partnership with Fab4 Consulting
510-439-1599
1901 Harrison St. Suite #1100 Oakland, CA 94612
Currently, Darryl, is a partner at Castellon Professional Services PC (CPS) providing various tax, accounting, and financial services, and manages the Oakland location. Darryl received his MBA in Finance from The University of Texas, at Austin, and holds a BA from UC Berkeley. Darryl was born, raised, and currently resides in Oakland, CA. He is currently raising 2 daughters both currently in college. Darryl is a lifetime member of the California Black Alumni Association, a member of Alpha Phi Alpha Fraternity, and has a passion for traveling, and learning of world history.