Paul A. Treinen, CPA

Paul Treinen, CPA

Managing Partner | Tax and Advisory Services Partner

714-978-1300 |

Paul has been with White Nelson Diehl Evans LLP since he began his public accounting career in 1990. He quickly advanced to the role of Partner in 2001 and Managing Partner in 2017, where he is responsible for overseeing a number of strategic and administrative items for the Firm. Paul formerly served as the firm’s Tax Director from 1997 to 2016. He is also currently a member of WNDE’s Executive Committee.

In his role as Managing Partner, Paul’s duties include, but are not limited to the following:

  • Overseeing the firm’s Management Committee
  • Developing and managing the firm’s overall budget and financial system
  • Promoting the firm’s culture and enforcing the firm’s core values & code of conduct
  • Overseeing and championing the firm’s strategic plan
  • Managing and participating in the firm’s business development plan
  • Ensuring the firm is a leader in human capital in attracting and retaining talent
  • Managing partner relations including teamwork, conflict resolution, coaching, and mentoring
  • Managing the firm’s overall accountability plan for partners and staff
  • Identifying the firm’s next leaders


Specializing in corporate and pass-through taxation, Paul also has a very robust individual client base. Like most partners in our Firm, Paul has vast experience dealing with manufacturers and distributors. He also has a number of clients that are focused in hospitality, retail, real estate, and senior care and aging services. He is an ardent believer in the value of tax planning, and has extensive experience with mergers and acquisitions, transactional issues, business formations, and strategic exit strategy planning.


Technical and Service Expertise:

  • Mergers
  • Acquisitions
  • Transactional Planning
  • Business Formations
  • Exit Strategy Planning
  • Extensive Experience Serving Continuing Care Retirement Community (CCRC)
    and Senior Living Entities

Industry Expertise:

  • Retail and Consumer Products
  • Hospitality
  • Real Estate
  • Senior Care & Aging Services (CCRC’s)

Professional Affiliations:

  • CalCPA
  • Pacific Club, Orange County

Community Involvement:

  • Member of Board of Governors, California State University, Fullerton Philanthropic Foundation
  • SCUHS Audit, Risk, and Compliance Committee Member


California State University, Fullerton

  • Bachelor of Arts in Business Administration with a concentration in Accounting

Certificate of Education Achievement in Business Valuations, AICPA