RoamTheWorldCellPhones.com

Cellphone GSM Frequencies: 900/1800

(This means you will need a GSM cellphone that will work on 900MHz or 1800Mhz to use it in Indonesia.)

Cellular carriers for Indonesia

Excelcom (XL)

Frequency: GSM 900/1800
Website: www.xl.co.id

Coverage Map (NONE)

Hutchison CP Telecommunications (THREE)

Frequency: GSM 1800
Website: www.three.co.id

Coverage Map (NONE)

PT Indonesian Satellite Corporation Tbk (INDOSAT)

Frequency: GSM 900/1800
Website: www.indosat.com

Coverage Map (NONE)

PT Natrindo Telepon Seluler (AXIS)

Frequency: GSM 1800
Website: www.axisworld.co.id

Coverage Map (NONE)

PT Telekomunikasi Indonesia Tbk

Frequency: GSM 1800
Website: www.telkom.co.id

Coverage Map (NONE)

PT Telekomunikasi Selular (TELKOMSEL)

Frequency: GSM 900/1800
Website: www.telkomsel.com

Coverage Map (NONE)

If you've used either of these networks or roamed in Indonesia, please post about your experience and the cost. Feel free to ask questions.