Thomas So is a partner at Mayer Brown JSM. He advises on shareholder and equity-related disputes, property-related litigation, libel litigation and media-related litigation work, and on litigation and arbitration in the PRC. He represents banks and financial institutions, property developers and corporations, as well as mainland China enterprises, in securities and equity-related disputes. He is dual-qualified in both Hong Kong and mainland China and provides legal support to clients and advice on cross-border dispute strategy in both jurisdictions.

Thomas has acted as both arbitrator and mediator in shareholder and other disputes. He is on a number of panel of arbitrators in Asia and has also acted as deputy judge at the District Court (2002), and as temporary deputy registrar at the High Court (2003/2004). He is a China-appointed attesting officer (appointed by the Ministry of Justice of the PRC). He is currently the president of the Law Society of Hong Kong.