Tourist visas issued by a Royal Cambodian Embassy abroad may appear to have a longer validity than 1 month. The validity of the visa refers to time you have to enter Cambodia. The visa is valid for 30 days from the actual date of entry into Cambodia. Make sure your passport is stamped on arrival, and keep the departure form. If you lose your departure form, you’ll need to contact immigration officials before you leave the country to make alternative arrangements. You can be fined, detained and deported if you overstay your visa. There’s a fine of $5 per day for overstaying the validity term of your visa. There’s no limit to this fine.
If you lose your passport with your Cambodia visa and corresponding entry stamp inside you’ll need to get an exit visa once you have received an Emergency Travel Document from the British Embassy. An exit visa will cost $40 and must be obtained from the Cambodian Immigration Department in Phnom Penh, 332, Russian Boulevard, Phnom Penh, Cambodia. The exit visa will take up to 3 working days to be processed.