Do Vietnam immigration officers require proof of onward travel at the border?

In June 2026 a traveler going from Cambodia to Vietnam by bus described the procedure at the land border: on entry, border officers ask for an onward ticket out of Vietnam. She shows a bus ticket for crossing the same border a month later, from Vietnam back to Cambodia. She considered the requirement to show an exit routine and saw nothing absurd about it. This is one person's experience at one crossing: at other checkpoints and when arriving by air the procedure may differ, so it is sensible to have an exit ticket — bus or flight — ready in advance.