If your volunteer program falls under the category "volunteer tourism", you can simply state "tourism" as your purpose of travel and get the tourist visa. This one is a little bit cheaper than the work visa, but it can
also just be extended for a total period of 60 days.
For this visa type, the Ministry of Foreign Affairs has launched an e-Visa process. It lets you complete an online application, pay with your credit card and receive your Visa via email. You then need to bring a
printed copy of it when you travel to Cambodia. Please be aware that the e-Visa will only be accepted at some airports, so keep that in mind when planning which visa to get and where to fly to.
Furthermore, the e-Visa process doesn't support the following countries: Afghanistan, Algeria, Arab Saudi, Bangladesh, Iran, Iraq, Pakistan, Sri Lanka, Sudan, and Nigeria. If you're from one of those countries
you have to apply for your visa at the nearest Cambodian embassy or on-arrival at all major checkpoints.
Fees for the Visa: USD30 + USD7 (processing charge)
Length of stay: 30 days (can be extended for another 30 days)
Required documents: A passport validity of more than six months at the time of entry, a recent passport-size photo in digital format (JPEG or PNG format), a valid credit card (Visa/MasterCard)
Ports supporting e-Visa when entering Cambodia: Bavet (Svay Rieng), Poi Pet (Banteay Meanchey), Cham Yeam (Koh Kong), Siem Reap International Airport, Phnom Penh International Airport