Malaysia currency only been issued in 1967

Malaya gained its independent on 31st August 1957. Sabah and Sarawak joined Malaya to form Malaysia on 16 September 1963. Do you know why Malaysia currency only been issued in 1967?

Bank Negara Malaysia has been given the authority to issue Malaysia currency since 1958. This authority was given under Bank Negara Tanah Melayu Ordinance 1958. The Board of commissioners of Currency Malaya and British Borneo still continued to issue currency until 12 June 1967. On 16 January 1969, the old Malaya currency legal tender value been ceased. Before that, it been circulated alongside 1st Malaysia currency since June 1967.