20 Sen - Hassanal Bolkiah 1st portrait

Brunei's first decimal coinage series was introduced in 1967–68 as the sultanate transitioned away from the Malaya and British Borneo dollar, which had circulated across the region since the 1950s. The new coinage tied Brunei to the Singapore–Malaysia–Brunei interchangeability agreement, under which coins of all three nations were accepted at par across borders — an arrangement that quietly collapsed in 1973 when Malaysia and Singapore went their separate monetary ways, leaving Brunei to continue honoring the pact unilaterally until it formally ended in 1979.