Lerche started his career as an assistant (
Auskultant) in Kammerkollegiet. On 12 July 1802, he was awarded the title of chamberlain (
hammerherre). From 7 December 1808 to 23 November 1810, he served as county governor of
Holbæk County. In 1832, he was appointed to the Assembly of 35 Enlightened Men ("de 35 oplyste Mænds Forsamling"). He was subsequently a member of Roskilde Constituent Assembly (the Stænderforsamlinger for Østifterne) from 1835 to 1846, elected by the estate owners on
Zealand. ==Property and titles==