According to updated LAW Number: 47/2014/QH13 On foreigners’ entry into, exit from, transit through and residence in Vietnam approved by THE NATIONAL ASSEMBLY of Vietnam, signed on June 16, 2014 by Chairman Nguyen Sinh Hung.

Article 20. Conditions for entry

A foreigner may enter Vietnam when fully meeting the following conditions:

1. Having a passport or an international travel document and a visa.

A foreigner who is eligible for visa exemption upon entry under an unilateral visa exemption scheme must have a passport that remains valid for at least 6 months, and the interval between the entry date and the previous exit date must be at least 30 days;

Swedish, Norwegian, Danish, and Finnish passport holders are exempted from requiring visas when they enter, exit or stay in Vietnam for less than 15 days. This is unilateral visa exemption policy from Vietnam government to attract more tourists to Vietnam. 

Decision No. 808/2005/QD-BNG issued by the Vietnamese Foreign Ministry on April 13 stipulates that these countries' citizens must have valid passports for at least three months since they enter Vietnam, return tickets or tickets for a third country. This does not apply to those who have been banned from entering or have not been allowed to enter Vietnam under Vietnamese laws.

According to the Resolution No. 39/NQ-CP dated on June 1, 2015 about visa exemption for citizens of the Republic of Belarus. Belarus citizens are exempted visa for entering Vietnam for a sojourn not exceeding 15 days, counting from the date of entry, regardless of their passport types and entry purposes, provided they meet all the conditions prescribed by Vietnam’s law. Please see below for details translated from  Vietnamese version.

Circular No. 157/2015/TT-BTC dated October 08, 2015 of the Ministry of Finance on collection, payment, management of fees for issuance of passports, visas, documents related to entry, exit, transit and residence in Vietnam 
10/8/2015 (good news : from 23 Nov 2015, stamp fee for visa on arrival at international airport of Vietnam will be $25USD for single entry visa & $50USD for multiple entry visa, please see below for details)

In a bid to boost tourism to the country, the Vietnamese government is all set to slash major portions of its visa fee assuredly in the near future. Round of talks have begun in the offices and the probable date from which the new fee will be released is said to be November 23rd 2015. The government has taken this serious measure to boost foreign arrivals in the country which have seen a major reverse in the past few years. 

Half your problem is solved when you have a visa expert who can get you your visa on arrival. Only a few people get this lucky when traveling to Vietnam as there is always a little trouble with the administrative work and finding an expert traveling agent who can get you a solid visa is all the hassle.