Cambodia utilizes the GSM mobile system, and Mobitel is the biggest operator, despite fierce competition. Pre-paid SIM cards (starting at $2) are readily available. As of April 2013, most street sellers and small private shops will offer pre-paid sim cards without requiring a passport. Major phone shops, on the other hand, will need a passport.
The majority of Cambodia has reliable 3G data service.
Landline numbers in Cambodia are formatted as +855 nk 123-4567, where “855” is the country code for Cambodia, the first digit of the area code, “n,” will be a 2, 3, 4, 5, 6, or 7 digit, and the second digit of the area code, “k,” will be a digit in the range 2-6 digit. (The leading zero visible in the domestic format is removed in the international version.) The last 6 or 7 digits of the subscriber’s number (joined with a hyphen) constitute the “local” portion of the number.
Mobile phone numbers start with a 1, 8, or 9, followed by seven or eight digits. A mobile phone’s entire number, such as +855 1 1234 5678, must always be dialed.
Internet cafés are inexpensive (US$0.50-1/hour) and widely available; even tiny communities will have at least one broadband provider. Rates in Kampot, Kratie, and Sihanoukville are about US$1/hour. Wi-Fi is becoming more popular, with connections accessible in unexpected locations such as fast food restaurants, pubs, and even petrol stations. Prices for domestic broadband vary from $29.95 to $89.00 USD.
Fast wireless 3G/4G internet (3.5G or 7.2 MBpS 3G/4G modem USB stick, unlocked 3G/4G modem costs US$30) is currently accessible in Phnom Penh, Siem Reap, and Sihanoukville/Kampot/Kep, with slower Edge coverage available in virtually all other locations. Tourists may add 3G/4G mobile Internet to their SIM card for as low as US$3/month (0.8GB max, LT3 package) (Metfone) or 1c/MB with Qbmore or an unlimited data plan for US$25/month (Metfone), and equip another 3G router to create a Wi-Fi hotspot to share Internet in your house/neighborhood.
Written Khmer, like Thai or Vietnamese, does not yet have a large presence in the electronic world. Phones and computers (and, as a result, Cambodian text messages, emails, social network slobbering, and web sites) are typically in English.
A trip to the post office in Cambodia, which was once a catastrophe, no longer meant saying good-by to your package. Intercontinental postcards should arrive in two weeks, whereas Asian postcards should arrive in one week. The prices are reasonable.