What should I do if I want to stay in Vietnam for 4 months. Could you help me to apply for a 4-month visa for Vietnam? Or I have to apply for a 3-month visa and then leave Vietnam and come back with another 1-month visa? Or can I enter Vietnam with 3-month visa and then get visa extended when I am in Vietnam? And one more thing, do I need to explain to the Immigration Officer that I will stay in four months, I have 3-month visa and then I will have visa extension?