His name is closely associated with the reform of the postal service, and with the introduction of the penny post. After repeated applications to parliament he succeeded in having a Royal Commission appointed in 1836 to report on the state of the posting department. Reports made by the commission supported the charges brought against this department, and prepared the way for reforms. Wallace was chairman of the committee that examined Rowland Hill's penny postage scheme; and it was by his casting vote that it was decided to recommend this scheme to parliament.