1. Valid Passport: Your passport should have at least six months of validity remaining beyond your planned departure date from Vietnam. It should also have at least two blank pages for visa stamps.
2. Visa Application Form: Complete the visa application form accurately and legibly.
3. Passport-sized Photos: Provide two recent passport-sized photographs that meet the specific requirements set by the Vietnamese embassy or consulate. The photos should be taken against a white background, with your face clearly visible.
4. Visa Approval Letter (for visa on arrival): If you are planning to obtain a visa on arrival at a Vietnamese airport, you will need to obtain a visa approval letter beforehand. This letter is issued by a Vietnamese travel agency or sponsor and must be obtained prior to your departure for Vietnam.
5. Proof of Travel Arrangements: Submit a copy of your round-trip flight itinerary or confirmed travel reservations to and from Vietnam.
6. Proof of Accommodation: Provide proof of your accommodation arrangements in Vietnam, such as hotel reservations or a letter of invitation from a host.
7. Financial Means: Demonstrate that you have sufficient funds to cover your expenses during your stay in Vietnam. This can include bank statements, traveler’s checks, or other financial documents.
8. Additional Documents: Depending on your nationality and the specific requirements of the Vietnamese embassy or consulate, you may be required to provide additional documents such as a letter of introduction or proof of travel insurance.

The duration of stay allowed on a tourist visa to Vietnam can vary. Typically, tourist visas are issued for single-entry or multiple-entry with varying durations of stay. The common duration of stay for a tourist visa is 30 days.

The processing time for a tourist visa to Vietnam can vary depending on the Vietnamese embassy or consulate where you apply and the workload of the visa processing department. In general, it can take anywhere from a few days to several weeks for a tourist visa application to be processed.