Simply, we called it emergency visa as you have definitely
send urgent email to vietnamvisabooking@gmail.com or call us +84 912685141 to
settle the issue the Approval Letter and the most important thing you should be
able to be online as we will send you the Approval Letter right away to enable
you to board the flight into Vietnam. 
Vietnam emergency visa can be arranged in 8 hours, 4 hours
or even 2 hours, in business day or at weekend or holiday. 
Cost will vary on the level of emergency/ weekend period of
time (Saturday morning/afternoon, Sunday morning/afternoon) but it is somewhere
from US$150 to US$170 per person. The urgent visa on working days costs about
US$32 - US$75, depend on time processing (8 hours, 4 hours or 2 hours). Learn more about Vietnam visa cost
We normally do not want you, as our customer, to spend so
much money to this. We would suggest you delay your flight then you will have
time to do normal visa into Vietnam.
In the case where you are in business and/or cannot delay
the arrival then we will be happy to help.
Please call us above or email us vietnamvisabooking@gmail.com, we are 24 hour online so this might be useful. 
Basically, you must have a valid Vietnam visa except you are
the citizenship of
visa exempted countries. 
The most convenient and, we can say, easiest way is to do
Vietnam visa on arrival (more about Vietnam visa on arrival) ie we send you Approval
Letter, you hold it to board your incoming flight and you pay visa stamp fee
locally to the Immigration - the stamp fee will depend on what type of visa you
would like to have. 
This will save your time sending request to Embassies and
wait probably long time while the price is certainly more expensive.