All foreign nationals need a visa to enter Vietnam. Tourist visas are generally valid for thirty days, cost $50-100, and take seven to ten days to process . In Southeast Asia, Bangkok is the most popular place to apply for a Vietnamese visa (four to five working days; $80).
At the time of writing, the majority of visas were being issued with specific start and end dates indicating the period of validity within which you can enter and leave Vietnam. However, a number of embassies and consulates, including that in London, are currently issuing visas with just the issue date and an expiry date, allowing greater flexibility; in this case the thirty days start ticking once you pass through Vietnamese immigration and you must have left the country before the visa expires. On arrival, you'll need the copy of your visa application form given to you when you collected your visa, plus a completed Arrival and Departure Card and a Baggage Declaration form. You'll need the Departure Card to register at hotels, and you'll need both forms when you eventually leave the country. Get all your shots recorded on an International Certificate of Vaccination , as some travellers entering Vietnam from China have been fined if they try to enter without one.
At the time of writing, thirty-day visa extensions were being issued through tour agents and travellers' cafés in Ho Chi Minh City, Hanoi and Da Nang ($30-40; three or four days), but the situation changes frequently, so check with the embassy before you leave. The fine for overstaying your visa is at least $50.