If you're planning to do a business visit in Vietnam, you need to get a business visa under sponsored by a registered company in Vietnam. This type of visa is granted for those who enter and remain in Vietnam for a purpose of Working for Vietnamese or foreigner enterprises operates in Vietnam or conducting business activities such as meetings, signing business contracts, etc. The required documents need to provide both from the applicant and the company. One of the important documents to apply for business visa is the Visa Approval Letter (Pre-Visa) from the Ministry of Public Security of Vietnam – your business partner in Vietnam will help you obtain this letter. Because once after submitting your documents to the Vietnam Immigration Department you do not have any chance to modify or change the passport number, proposed date of entry, place to collect visa, so these information must be correct.