100 Dollars HSBC

The Hongkong and Shanghai Banking Corporation's right to issue banknotes in Hong Kong is one of the more unusual arrangements in modern banking — a commercial institution, not a central bank, putting currency into circulation under licence from the government. During the period this series was issued, that arrangement survived the 1997 handover intact, with the three note-issuing banks continuing under essentially the same regulatory framework, now overseen by the Hong Kong Monetary Authority rather than the colonial administration.

Thomas De La Rue's involvement here is unremarkable by itself — they printed for HSBC throughout much of the twentieth century. What matters is the continuity: the same issuing privilege, the same printer, the same series number running across the sovereignty transfer without interruption.