011855 and +855 often work interchangeably from cell phones (use also to text Cambodian numbers).
Battambang | 53 | Kampot | 33 | Siem Reap | 63 |
Kampong Cham | 42 | Kandal | 24 | Sihanoukville | 34 |
Kampong Chhang | 26 | Phnom Penh | 23 | Sisophon (Saophoan) | 54 |
Kampong Speu | 25 | Poipet (Paoy Paet) | 54 | Suong | 42 |
Kampong Thom | 62 | Pursat | 52 | Ta Khmau | 23 |