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 – 23rd 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 Whippany in the News
NJBIZ Names Two Withum Leaders to Finance Power List
Pat Walsh Pat was recognized for his relentless dedication to elevating Withum’s position as a top 20 advisory, accounting and tax firm. This recognition reflects Pat’s leadership and the Firm’s consistent year-over-year growth and strategic expansions into new markets under his guidance. His commitment and contributions to the profession have earned him numerous accolades, including…
Steve Talkowsky Named NJBIZ 2026 Leader in Finance
As a respected leader, Steve was recognized for his impact on the Firm’s Tax Services Team, contributing to the practice’s growth, and for his strong commitment to the mentorship and development of the teams he leads. He serves clients with global operations, advising on business taxation matters with deep expertise in Subchapter C, S corporation and partnership taxation. With a focus on making complex tax matters accessible, he is…
ROI-NJ Names Withum Leaders to Annual Power List
Pat Walsh Pat Walsh, Managing Partner and CEO, has led numerous firmwide strategic initiatives focused on best practices, client experience and technology. He leads Withum’s national growth strategy and client service initiatives, with a focus on innovation, talent development and expanding the Firm’s advisory capabilities to meet clients’ evolving needs. Pat was recognized for his…
Forbes Names Thirteen Withum Leaders to Its Best-In-State CPAs List
Withum’s representation reflects the Firm’s collective power of people, reinforcing its position as a leading national advisory, tax and audit firm. From the East to the West Coast and representing a broad cross-section of services and industries, the Withum advisors listed reflect diverse expertise and leadership styles, united by a shared commitment to client and community service. Withum’s 2026 Best-In-State CPAs New Jersey New…
BINJE Names Marcus Dyer to 2026 Best Black Business Leaders List
Marcus draws on his law background to represent clients in commercial and tax disputes before state courts, Federal District Court and the United States Tax Court, frequently resolving matters through alternative dispute resolution rather than litigation. As an industry thought leader, Marcus contributes to a wide range of publications, helping businesses and individuals navigate high-risk…
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