James Warner is a former principal in Ernst & Young's National Tax Department and now tax attorney for Walmart. He was the Mergers & Acquisitions leader for the Online Tax Advisor and he specialized in the area of consolidated returns and general Subchapter C issues. Through the ABA Tax Section and his consolidated returns practice, Warner was actively involved in working with the Treasury and the IRS in developing the consolidated returns regulations.

He has almost 20 years of mergers and acquisitions experience and has taught a consolidated returns course as an Adjunct Professor for the Georgetown University LL.M program. He clerked for the U.S. Tax Court and was an attorney with the IRS Chief Counsel before going into private practice. Warner earned a J.D. from the Ohio State University College of Law, and an LL.M in Taxation from the Georgetown University Law Center, where he graduated first in his class, and he also is a CPA.