The standard processing time of the e-visa is 3-5 business days. However, there are instances when this will be delayed. This is especially the case if you’re applying during the holidays where most of the government offices are closed. To avoid any delays, it’s highly recommended that you apply for the visa at least two weeks before your trip.
But if you need to leave for Vietnam in a few days and you need the visa ASAP, you can choose the rush option for the processing. It will cost more but you’ll get your visa within 24 hours.