The official currency of Indonesia is the rupiah (Rp) which is subdivided into 100 sen. Inflation has left all notes and coin denominated in sen obsolete.
Informally, Indonesians use the word perak, which means silver, to refer to rupiah. For many years the Riau Islands and the Indonesian part of New Guinea had their own versions of the rupiah. These were absorbed into the national rupiah in 1964 and 1971 respectively.
The rupiah has experienced various devaluations and reissues. Currently the notes circulating date from 2000. Notes from 1998-1999 are no longer legal tender but can be exchanged at Bank Indonesia until 31st January 2018.
Banknotes come in denominations of 1,000, 2,000, 5,000, 10,000, 20,000, 50,000 and 100,000 rupiahs. The Rp1,000 note is far more common than the Rp1,000 coin. You will see even small transactions such as buying a bus ticket taking place with a note rather than a coin.
There are currently two series of coins in circulation. The aluminium, bronze and bi-metallic coins from 1991-1998 and light weight aluminium coins from 1999-onwards.
Coins are available in the following denominations:
Due to the low value and overall shortage of coins in denominations less than Rp100 it is common to have amounts rounded up or down. Sometimes in shops you will be given sweets in lieu of small amounts of change.