Greetings. Am considering a 1 year, multiple entry business visa for US Citizen (DN Visa). My understanding is that I will NOT have to leave Vietnam every 90 days. However, will I have to report to the local immigration office every 90 days? If living in Nha Trang is there an immigration office there? I've read that holders of 1 year business Visas need to report to the local police department and provide documents for them to open a "file". Then, every 90 days, the visa holder needs to take the "file" to the local immigration office where they stamp some documents and the visa holder must return the updated "file" to the police department. Can anyone confirm what the reporting requirement is for this class of visa holder? THANK YOU.