Our Team

Brien P. Batley, CPA

Founder, Member

Brien is the founder and member of Batley CPA, LLC. He specializes in tax compliance, research, and representation for closely held businesses and their owners; structuring mergers and acquisitions; business valuation; CFO services including overall financial management, assistance with procuring financing, financial forecasts, projections, analysis, assistance to troubled businesses, and specialized costing projects.

Brien is a graduate of Marquette University with degrees in accounting and finance. He has also completed the Masters of Science – Taxation program at UW-Milwaukee. He is a member of the AICPA and WICPA.

Brien started his career at KPMG in the tax department. He has held positions of CFO and controller of two publicly held companies and two large privately held companies gaining in depth experience in high-tech manufacturing, wholesale distribution, and the construction industries.

E-mail: [email protected]

Sharon Rotter

Payroll Manager – Green Bay

Sharon is the lead payroll specialist at Batley CPA, LLC. She handles the set up and processing of both live and after-the-fact payrolls for Batley CPA clients.

Sharon joined Batley CPA in 2009. Sharon came to us with sixteen years of valuable experience as an office manager, bookkeeper and payroll specialist for both large and small service and manufacturing businesses.

Sharon can be contacted in the Green Bay office at [email protected].

E-mail: [email protected]

Aaron Wintheiser, CPA

Member, Neenah Office

Aaron is manager of the Neenah office of Batley CPA, LLC. Aaron handles monthly accounting, payroll processing, and preparation of individual and business tax returns.

Aaron graduated Summa cum Laude from the University of Wisconsin-Oshkosh with a degree in accounting. He began his professional career with Batley CPA in August 2010.

E-mail: [email protected]

Nathan Oukrop, CPA

Appleton Office

Nathan is a Tax and Accounting Manager in our Appleton office location. He specializes in tax compliance, research, and representation for closely held businesses and their owners; assists businesses through mergers and acquisitions; CFO services including overall financial management, financial forecasts, projections and analysis, bookkeeping and financial statement preparation.

Nathan is a graduate of Hamline University (St. Paul, MN) with a degree in accounting. He is a licensed CPA and is an active member of both the AICPA and WICPA.

Nathan has worked in Public Accounting his entire career and has worked his way up into the Tax and Accounting Manager role. He actively works in many different industries that include manufacturing, construction contractors, retail, technology, and hospitality.

Christine Novak, CPA

Appleton Office

Christine is a senior staff accountant at Batley CPA, LLC, where she provides monthly accounting services and financial statement preparation, performs tax research, and prepares individual, business, nonprofit and fiduciary tax returns.

Christine has a degree in accounting from Marquette University. She is a licensed CPA in Wisconsin and a member of the AICPA.

Before joining Batley CPA in 2025, Christine spent nearly 24 years with National Association of Tax Professionals (NATP). During her time at NATP, she conducted federal tax research for tax professionals nationwide and developed technical content for continuing professional education (CPE) courses. Christine has extensive experience providing guidance on a wide range of complex tax issues.

E-mail: [email protected]

Anthony “Tony” Karl, CPA

Green Bay Office

Anthony “Tony” Karl joined Batley CPA, LLC in 2015 and currently serves as the manager of the Green Bay office. As a licensed CPA since 2020, Tony provides a broad range of tax, accounting, and advisory services to individuals and businesses.
With experience spanning a variety of industries and tax matters, Tony focuses on assisting clients in navigating everything from tax planning and compliance to financial reporting and business-related decisions.