What should you know about immigration and arrival/departure procedures at Ho Chi Minh City (Tan Son Nhat) airport?

The online entry form must be filled in English — entering one field in a non-English language caused the system to reject it, requiring a full resubmission. Also complete any required online check-in/registration well in advance: one traveler had to rush through it just 30 minutes before departure, since airlines won't board passengers without it.

It's easy to get in the wrong immigration queue on arrival: one traveler followed a crowd of passengers from other flights (Indian, Japanese travelers) after a bathroom stop and waited 15-20 minutes in a line that turned out to be for a different flight without immigration processing. Tip — ask airport staff right away which line you actually need.

A smooth border crossing in the past doesn't guarantee the same result next time: almost a year after a previous successful trip, one traveler was turned back at the "green corridor" checkpoint and handed an official notice of removal from the flight — apparently due to a temporary exit restriction in effect at the time.