A regular tourist visa for Vietnam is available for 1 or 3 months. Once you have a visa it’s possible to extend your visa in the country and save yourself the time and money of doing a visa run. While there is no published official amount of time that you can extend your visa in-country, visitors have been known to be questioned when extending for the third or fourth time. Thus it is a good idea to leave the country and restart a new visa.
If you need to do a visa run from Ho Chi Minh City here are the best options.
Bus To Phnom Penh
By far the cheapest option is to get the bus to Phnom Penh in Cambodia. Numerous buses leave throughout the day from the Pham Ngu Lau area.
Just go to any one of the many travel agents in Pham Ngu Lau and buy a ticket there. Tickets are from $20 USD and the trip takes 7-8 hours, depending on traffic and the queue at the border.
Here is how to go from Ho Chi Minh City to Phnom Penh by bus.
The cheapest flights out of Ho Chi Minh City are almost always the low cost airlines, with the closest cities being Bangkok, Kuala Lumpur, and Singapore.
It is also worth checking Skyscanner to see if there are any good deals going on with the full service airlines.
When flying back you need to arrange your visa online first.
There is no railway between Vietnam and Cambodia yet. There are plans for a Ho Chi Minh City – Phnom Penh railway, but that is years away from being a reality.