Can I check-in and board the flight to Vietnam without the Visa approval letter?

What should I do if I find out that I completed the Visa application form with wrong passport information?

What is stamping fee at Vietnam airport and how much is it?

How much does Visa on arrival cost?

How long prior the trip should I apply for a visa?

What procedures at Vietnam airport to pick up the visa?

Should I provide the exact entry date to Vietnam?

What documents to pick up the Visa at Vietnam airport with Visa on arrival?

What is requirement of passport expiry for Visa on arrival?

How many photos I need for Visa on arrival? What is its size?