William J. Kolarik II, Tax Attorney in Baton Rouge, Louisiana

Willie Kolarik is an attorney and certified public accountant at Kean Miller in Baton Rouge, Louisiana, where he focuses his practice on Litigation and Controversy – Tax and Tax Law. He serves as tax counsel to many large domestic and international businesses across a wide range of industry sectors, including energy, financial institutions, manufacturing, industrial products, retail, consumer goods, healthcare, gaming, entertainment, and utilities. His background includes in-house Fortune 100 experience and work with major consulting firms, along with more than two decades of experience advising on state and local tax matters involving income, franchise, sales and use, gross receipts, property, payroll, and other transaction-based taxes.

Willie represents and advises U.S. and international corporations, partnerships, private equity funds, limited liability companies, individuals, and tax-exempt entities on a broad spectrum of state and local tax issues. His practice regularly involves tax controversy matters, including complex income and franchise tax audits and litigation addressing transfer pricing, expense attribution, and the computation of the tax base for multi-tiered corporate groups. He also advises clients on state and local tax considerations related to commodities and derivative transactions for financial institutions, commodities traders, and energy companies, including both physical and financial transactions involving base metals, sugar, coffee, grains, natural gas, oil, and electricity.

A significant portion of Willie’s practice is devoted to state and local sales and use tax matters, including those arising under Louisiana’s decentralized local sales and use tax system. His tax controversy work includes representing clients before state and local taxing authorities, administrative tribunals, and courts throughout the country.

Willie also advises on tax and tax-related regulatory accounting issues associated with public utility ratemaking, including normalization and consolidated tax savings adjustments. In addition, he has substantial experience with mergers and acquisitions, particularly in the energy industry, and has worked on transactions for private equity firms and strategic investors involving both regulated and unregulated entities.

With experience navigating state and local tax systems nationwide, Willie provides research, analysis, and commentary on judicial, administrative, and legislative developments affecting state and local taxation. He assists both commercial and governmental clients with tax policy discussions, multistate tax planning, and compliance considerations.

In addition to his client work, Willie is a published author whose articles have appeared in The Tax Lawyer, Tax Notes, and other publications. His research has been cited in testimony before the U.S. House Committee on the Judiciary, in a petition for a writ of certiorari and an amicus curiae brief submitted to the United States Supreme Court, in an amicus curiae brief to the Illinois Supreme Court, and in several peer-reviewed law journals. He is a Fellow of the American College of Tax Counsel and serves as an Adjunct Professor of Law at Louisiana State University’s Paul M. Hebert Law Center, where he co-teaches the Taxation of Business Entities course. Willie has been recognized by The Best Lawyers in America (2025–2026) and Chambers USA (2025).

Before joining Kean Miller, Willie worked at a large regional law firm and in Ernst & Young’s National Tax Department, Indirect Tax Practice, where he collaborated with the Power and Utilities group, the Indirect Tax Controversy group, and the State and Local Tax Center for Tax Policy. Earlier in his career, he worked in-house at The Walt Disney Company, supervising federal, state, and local tax compliance matters for the Cable and Broadcasting group and assisting with state income tax planning projects, corporate restructurings, exposure analysis, legislative analysis, and state income tax provision matters. He brings this in-house perspective and practical understanding of business operations to his tax litigation and advisory practice today.