Is it possible to convert TRC to student visa?

Valerie Choose wrote:

I've got trc from my employer. I applied my son as dependent but it seems student visa has longer validity.

So I take you are able to renew your TRC's?, I can't see any reason why your son can't apply for a student Visa, living in Hanoi does have some advantages, at least you might be able to get the correct info directly from the horse's mouth, so to say, in smaller cities they won't admit when they don't know something and will often tell you the wrong answer. So best to go into Immigration and ask them, you can probably download application forms in English, so you will know what is required.
How old is your son, he will be required to attend a certain amount of lessons, and then there will be the extra costs???, probably easier to leave him on the TRC?
   Good Luck.