He focuses primarily on advising on domestic and international tax planning, the taxation of financial instruments and derivatives, cross-border financing, CLOs, securitizations and other structured finance transactions. Jack also has significant experience in advising on fund investments, cross-border and domestic real estate transactions, including financing structures, REITs and fund structures, debt restructurings and global corporate transactions. In addition to private practice, Jack served for two years as attorney/adviser to the Honorable Arthur L. Nims, III, Chief Judge of the U.S. Tax Court. 

Jack has been ranked as a leading tax lawyer in Chambers USA and as a recommended lawyer in Legal 500 USA. He is also listed in the Super Lawyers directory. Chambers says “Jack Heinberg of Allen & Overy LLP ‘is admired by clients for the creative and thoughtful advice he offers in cross-border financing and securities, derivatives and financial instruments, and international and domestic tax planning. He is valued for being a great communicator and 'one of the easiest tax lawyers to talk to.’''