10 Sen

Riau — the Indonesian archipelago province bordering Singapore — had its own distinct currency series from 1963, intended to manage cross-border currency flows with Singapore and Malaya. The 10 Sen of 1962 was struck in anticipation of that system, giving it a production date one year before the series formally entered circulation. The Riau rupiah was abolished in 1964 when Jakarta ended the regional currency experiment, meaning the entire series saw barely a year of official use.