Compared to many neighboring countries, Cambodia is relatively relaxed about private drone flights, general registration isn't required. Sensitive areas like Angkor Wat or Phnom Penh, however, have strict special rules with paid permits.
Outside sensitive zones, drone flying in Cambodia is possible without prior registration. Anyone flying more regularly or commercially should still submit a flight plan and proof of insurance to the SSCA (State Secretariat of Civil Aviation).
Flying over the Angkor temple complex is only allowed with a permit applied for in advance. Several approvals are needed at once, including from the APSARA Authority (responsible for Angkor Park) plus air traffic control clearance due to the proximity of Siem Reap Airport. Combined costs run around $500 to $1,000, processing takes up to 15 working days.
Flying is also banned over the Royal Palace in Phnom Penh, near government buildings, military facilities and airports. Without written permission this also generally applies to temple complexes across the country.
Questions about permits and current rules can be directed straight to the SSCA, ideally at least 2 to 3 weeks before your trip. Processing time varies between 5 and 15 working days depending on the authority and the plan.
In restricted zones like Angkor Park or other sensitive areas, consequences range from a warning through confiscation of the drone to fines between $200 and $500 or detention.
For normal travel footage away from temples and cities, Cambodia is uncomplicated. Anyone who really wants to film over Angkor Wat should plan the permit process well in advance and budget for the extra costs, for most travelers it's probably not worth it.