Thomas has a broad civil practice, encompassing public, commercial, professional discipline, and employment law. He has particular interests in judicial review (both public and commercial), commercial litigation and arbitration, and human rights and civil liberties, but accepts instruction in all areas.

During his pupillage, Thomas assisted his supervisors in cases before the High Court (Administrative, Commercial, and Mercantile Courts), Chancery Division, and Court of Appeal, and before several arbitral tribunals (under ICSID, ICC, and LCIA rules) and professional discipline panels. In so doing, he gained litigation and advisory experience across a broad range of practice areas, from commercial litigation and arbitration to chancery, employment, professional discipline, (public and private) international, public, and human rights law.