Timo banking is not a government authority, however, they have done a good job of quoting and explaining new regulations regarding foreigners (from any country) opening new bank accounts in Vietnam:
https://timo.vn/en/blog/regulations-for-foreigners/
Pertinent points:
In addition to a valid passport, you need a 12 month Visa on arriving in Vietnam in order to immediately open a bank account.
That doesn't mean the bank is required to open an account for you.
It means the bank can't open an account without a 12 month Visa
However, there are other documents which will allow you to qualify.
This is a quote from the Timo website:
One of the following valid documents with at least 12 months validity*:
+ Vietnam visa, OR
+ Temporary resident card, OR
+ Permanent resident card
*The above documents do not need to have 12 months remaining validity from the date of applying to join Timo.
Information about Temporary Resident Cards can be found in this sticky thread:
https://www.expat.com/forum/viewtopic.php?id=541937
Once you apply for and get a TRC or PRC, you can then open an account.
WHAT ABOUT TEACHERS and others hired for jobs while possessing a visa of less than 12 month's duration?
Maybe Rick (Budman) or someone else can dig deeper and see if there are exceptions.
Previously a legitimate employer could help you set up your first account and pay you through your bank account.
Please feel free to post any corrections based on fact.
There is already a lot of rumor and heresay about this subject posted throughout the forum.