Shawn is a US Tax Controversy Leader
International Tax Review's Tax Controversy Leaders 2015 (5th Edition)
Shawn O’Brien is a Tax partner who represents clients in all types of tax disputes with taxing authorities on international, federal and state levels. He routinely advises clients on various tax issues during tax examinations, in administrative appeals and as an advocate in trial and appellate litigation before the US Tax Court, US District Courts and US Court of Federal Claims. Shawn's tax controversy and litigation experience spans a broad range of areas, including transfer pricing controversies, debt v. equity issues, international withholdings, advance pricing agreements, “tax shelter” disallowances, research and development tax credits, excise taxes, and changes in accounting methods.
Shawn advises foreign and domestic corporations, partnerships, MLPs, and LLCs seeking corporate and tax advice in connection with various types of foreign and domestic transactions, including 1031 exchanges, mergers and acquisitions, restructurings, divestitures, leveraged buyouts, structured financings, and oil and gas transactions. Shawn is a Certified Public Accountant (CPA) licensed in Louisiana.
Shawn is particularly focused on a variety of tax issues facing the energy industry including tax controversy, joint ventures, restructuring, acquisition and disposition of energy assets. Shawn served as Chair of the Energy and Natural Resources Committee of the State Bar of Texas Tax Section from 2011 to 2013.
According to International Tax Review's “World Tax” 2014, Mayer Brown's Houston tax practice is "known for its sophisticated transactional tax and tax controversy work. Clients recognize the quality of its lawyers, many of whom have extensive backgrounds in the energy sector. The practice is strong in international tax, and advises both US and non-US multinationals on their energy investments. The practice is also strong in transfer pricing and controversy, and has represented clients in some of the biggest transfer pricing disputes filed in US courts. The Houston practice is led by Shawn O'Brien, who focuses on tax controversy."
Mayer Brown was recently named Tax Controversy Team of the Year for the second consecutive year in the Legal 500 United States Awards. "Mayer Brown is 'among the best' and fields a large team…dedicated exclusively to tax controversy and transfer pricing," said Legal 500 and its sources in the US edition. The firm is “regularly seen in the most high-profile controversy cases before the US Tax Court” and produced “yet another impressive run of work” in 2014. Additionally, the practice has been honored by the International Tax Review as the North America Tax Disputes Firm of the Year, US Tax Court Firm of the Year, US Transfer Pricing Firm of the Year, North America Transfer Pricing Firm of the Year, Chicago Transfer Pricing Firm of the Year, Dallas/Houston Tax Firm of the Year, San Francisco Area Transfer Pricing Firm of the Year, San Francisco Area Tax Firm of the Year, and Washington, DC Tax Firm of the Year.