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
Los Angeles Business Journal Names Two Withum Partners as Top Advisors in the San Fernando Valley
Chris Passmore and Steve Martini have made a lasting impact across the San Fernando Valley through their leadership, business advisory skills and community involvement. Recognized for helping businesses navigate change, create opportunity and drive growth, they have strengthened the region’s business community while contributing to its long-term economic vitality. Chris Passmore is the Partner-in-Charge of Withum’s…
Withum Names Eighteen New Partners
Introducing Our 18 New Partners
Withum Announces 2026 Firmwide Leadership Transitions
This next generation of leaders step forward at a pivotal time for the Firm, bringing the technical expertise and strategic perspective needed to navigate continued growth, rapidly advancing technology and an ever-evolving industry landscape. Grounded in the Withum Way mentality, they will shape what’s ahead while preserving the culture that remains central to how the…
Withum’s Columbia Office Welcomes Greater Baltimore
Withum team members, clients and community leaders, including representatives from Howard County and the Central Maryland Chamber, came together to mark the official “door opening” on the new location. The ribbon-cutting ceremony highlighted the evening, which featured citations presented by community leaders welcoming Withum to the Columbia region and recognizing its strong ties to the…
Nadia Matthie Appointed as Chair of the AICPA’s Employee Benefit Plans Expert Panel
The AICPA’s Employee Benefit Plans Expert Panel was formed to protect the public interest and agree on key plan issues by leveraging the knowledge of leaders in the employee benefit plan industry. Nadia’s deep expertise makes her a valuable asset to help further the panel’s mission as Chair of the group. Nadia has more than…
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