All nationalities need to apply for a travel visa, except for nationals from the following countries: Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam.
A visa on arrival, valid for a 30 day stay, is specifically granted at Phnom Penh International Airport, Siem Reap International Airport, and International Border Checkpoints. Visas are also granted at Royal Cambodian Embassy or Consulate abroad. The visa fee for a tourist is US$20, and the visa fee for a businessman is US$25. Visas can be extended at the Immigration Department in Phnom Penh City. A free visa (K) is expressly granted to the Cambodian living overseas.
The Royal Government of Cambodia has recently approved e-visas. All you have to do is complete the online application form available at the official website (evisa.mfaic.gov.kh), pay by credit card online, and include uploading a recent passport-size photo in JPEG/ PNG format. The visa will be approved within three working days, allowing you to breeze by that lengthy line and get a jump-start on your holiday.
The e-visa, valid for a 30 day stay, is available only for a typical tourist visa for a single entry. It is currently not available for nationals from Iran, Iraq, Pakistan, Afghanistan, Bangladesh, Arab Saudi, Algeria, Sudan, and Sri Lanka. For a business visa, please apply at your nearest embassy or on arrival at all major check points.