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 Bulgaria.)

Cellular carriers for Bulgaria

Bulgarian Telecommunications Company AD (vivatel)

Frequency: GSM 900/1800
Website: www.btc.bg

Coverage Map (NONE)

Cosmo Bulgaria Mobile EAD (GLOBUL)

Frequency: GSM 900/1800
Website: www.globul.bg

Coverage Map

Mobiltel EAD (M-Tel BG)

Frequency: GSM 900/1800
Website: www.mobiltel.bg

Coverage Map (900Mhz)
Coverage Map (1800Mhz)

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