He joined Gibb, Livingston & Co., a prominent trading firm in Hong Kong and China, and became a partner in July 1868 following the retirement of Edward Ford Duncanson and William Henry Gibb.
Lowcock married Annie Loftus Russell on 7 June 1873 at St John's Cathedral, Hong Kong.
According to her inscription on their shared gravestone in Wimbledon, London, "our only child" was Henry Christopher, buried in Hong Kong.
Henry Lowcock served in the No.320 Maintenance Unit of the Royal Air Force during the Second World War, and was killed in a shop accident in Karachi.
[4] His son, Sidney James Lowcock, was the seventh headmaster of Diocesan Boys' School from 1961 to 1983.