Tax Services
Whippany, NJ
Located in the heart of Morris County, minutes from Morristown Business District, Withum is one of New Jersey’s top-ranked accounting and advisory firms, providing reliable audit, tax and consulting services to businesses locally and nationwide.
Withum’s Whippany office has an industry focus on financial services, technology, healthcare, manufacturing, distribution & logistics and private equity. With an onsite state-of-the-art cybersecurity facility, Withum’s CPAs and professionals provide quality accounting services…plus a suite of advisory solutions to help businesses grow and thrive with the personal touch they deserve. That’s the Power in the Plus!
(973) 898 9494
Whippany Service Specializations
Accounting Advisory and Financial Reporting
Audit Services
Employee Benefit Plan Audits
Private Client Services
Wealth Management
Forensic and Valuation Services
Transaction Advisory
Cybersecurity
New Jersey State and Local Tax Updates
Do you or your organization operate in multiple states? Do you own property in a variety of states? New Jersey State and Local Tax (SALT) laws are always changing and understanding the nuances of the states that you own or operate in is challenging. In these New Jersey resources, you’ll find just a dash of the most up-to-date details on rules and regulations as state and local tax changes happen by state!
Industries We Focus on in Whippany
Beyond the Region
- Inside Public Accounting Top 100 Firms – 22nd Largest Nationally
- Accounting Today Top 100 Firms – 22nd Largest Nationally
- Great Place to Work® – Fortune Best Workplaces for Parents and Women
- Vault Top 25 Accounting Firm
Partner In Charge
Zsia Rosmarin, CPA, MSBased in the firm’s Whippany office, Zsia is a Partner and Team Leader of the firm’s Technology and Emerging Growth Services tax practice with over 20 years of professional experience specializing in taxation including private and publicly held multistate and multinational companies. She has a deep expertise assisting corporate clients with ASC 740 Tax Provisions and Tax Compliance.
Zsia leads the Tax Tech and Emerging Growth Industry Group where she consults on a wide variety of related tax issues including diligence ready assessments, secondary transactions, qualified small business stock, tax credits and incentives (i.e. R&D, excelsior, QETC), state taxes including sales tax and international taxes. Zsia is the Founder and leader of the Firm’s Women in Technology Group.
She resides in Somerset County, NJ. Previously, she was a partner at a large national accounting firm and a senior manager at a “Big Four” firm.
Whippany Leadership
Withum in the News
Chris Passmore Named Top Leader on Los Angeles Business Journal List for Fourth Consecutive Year
As partner-in-charge of Withum’s Los Angeles office, Chris plays a pivotal role in the Firm’s growth on the West Coast. With nearly 25 years of experience in the profession, he specializes in assurance and business consulting services to emerging and middle-market companies. In addition to serving technology companies and professional services firms, Chris holds an advanced-level certificate in 401(k)…
Kerra Diener Named as 2026 Los Angeles Business Journal Top 100 Accountant
Kerra Diener is a partner in Withum’s Los Angeles, CA office, advising multinational and multistate businesses on complex federal and state tax matters. Known for her specialized technical depth, she helps corporate and private clients across industries, including industrial and consumer products, real estate, theatre and entertainment and cannabis, with expertise spanning tax planning, compliance, M&A and consulting. The accolade…
CalCPA Names Withum Leaders to 2026 NorCal Top 50 Accountants
Top 50 Accountant Honorees at Withum Brandon Yip Brandon Yip is a partner who leads Withum’s Technology and Emerging Growth Services Team in the San Francisco Bay Area. He focuses on advising public and private companies on audit, regulatory and transactional matters while helping innovation-driven organizations scale. Deeply connected to Northern California, he supports the region’s technology and life sciences ecosystem…
Fortune Media and Great Place to Work Name Withum Among Best Workplaces in New York
Ranking at number 22 on the Large Business list, Great Place to Work recognized the Firm for its strong culture and team-centric approach, highlighting its distinctive benefits such as flexible schedules, childcare benefits and time off. The recognition also spotlighted Withum’s collaborative environment – prioritizing professional development, open communication, innovation and work-life balance, enabling team…
Withum Champions Veteran Initiatives and Community Impact
Wreaths Across America For more than five years, Withum has been an active participant in the Wreaths Across America initiative, which is championed by the Firm’s Veterans Team Member Resource Group (TMRG) and the Not-for-Profit Services Team. Wreaths Across America (WAA), is a national nonprofit dedicated to remembering fallen service members, honoring those who serve…
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