I had originally said on my application I would enter and exit from SGN. However if I change my plans, am I allowed to enter or exit from HAN instead?
Which type of visa do you have now?
If you had evisa, you have to enter exactly arrival port which put in the application form
If you had visa on arrival, your approval letter is valid for all international airport so you can change entry/exit port
With both type of visa, you can leave VIETNAM through HANOI without any problems