You should apply for a visa two months before you plan to travel if you think you need one.
You can apply for either a single- or multiple-entry visa to Cambodia.
This is necessary because several agencies and their systems check your visa paperwork.
In certain cases, a brief trip to Cambodia might take as long as a month or more to secure a visa. When planning an extended stay in Cambodia, you'll need to wait at least four weeks before applying for a visa. .
A visitor to Cambodia can only remain for 90 days out of a total of 180 days on a tourist visa. After applying for and receiving a visa to Cambodia, the government of that country will decide whether to permit you to remain in the nation for a specified time. If you didn't assume you'd get the full 90 days, you'd be in a better position. There is no assurance of this.