The rupiah (Rp) is the official currency of Indonesia. Issued and controlled by the Bank of Indonesia, the ISO 4217 currency code for the Indonesian rupiah is IDR. Informally, Indonesians also use the word "perak" ('silver' in Indonesian) in referring to rupiah. The rupiah is subdivided into 100 sen, although inflation has rendered all coins and banknotes denominated in sen obsolete.
The Riau islands and the Indonesian half of New Guinea (Irian Barat) had their own variants of the rupiah, but these were subsumed into the national rupiah in 1964 and 1971 respectively (see Riau rupiah and West New Guinea rupiah).