Border crossing have become more regulated over the past few years and the corruption and minor bribery that used to be commonplace has diminished dramatically. There are five main border crossings between Vietnam and Cambodia, the busiest and most popular being Moc Bai–Bavet, with a regular bus service between Ho Chi Minh City and Phnom Penh; this is the recommended way to go. When getting on the bus to return to Vietnam from Phnom Penh, the driver’s assistant will ask you for your passport, which will be kept until you reach the border. This may appear strange, but it's the standard procedure, so don’t worry. Other crossings include Ving Xuong–Kaam Samnor, on the river, if you’re traveling by boat; Tinh Bien–Phnom Den, if you are traveling to or from Kep; and O Yadao–Le Thanh, if you want to cross into the north of the country.
The following border points are open with Thailand (Thai border towns in parentheses): Koh Kong (Hat Lek), Pailin (Ban Pakard), Duan Lem (Ban Laem), Poipet (Aranyaprathet), O'Smach (Chong Jom), and Anlong Veng (Chong Sa Ngam). From Laos you can cross at Dom Kralor (Voeung Kam). Overland crossings through Poipet and Koh Kong are the most popular, but bear in mind that Cambodian roads remain arduous, particularly in the rainy season. Coming from Laos overland, the only way to continue into Cambodia is by boat or bus to Stung Treng, then on from there the following morning.