Visa to Vietnam

First thing comes first, getting Visa to Vietnam is not complicated generally but requires some days and paper works. Evisa is not availble yet
No matter which way of access you choose, a Vietnamese entry visa is required for all foreigners, except for citizens of countries having bilateral agreements on visa exemption with Vietnam.

Types of Visa to Vietnam

• Diplomatic and official visa: No fees unless otherwise agreed upon between Vietnam and applicant’s country. On applying this visa, you must submit an official letter from the concerned agencies of local government, foreign embassies or consulates accredited to the country, international organizations, or other accredited organizations based in that country.
• Business visa:  On applying this visa, you should obtain an approval through your sponsor in Vietnam. It’s generally much easier to apply once in Vietnam. Multiple entry and stay of three-month or six-month is possible.
• Tourist visa: It's what you need to enter Vietnam!  Available one-month single-entry visa (maximum stay in Vietnam of one month). Tourist visa may be extended one time for 30 days after your arrival in Vietnam. If you plan to spend more than a month in Vietnam, or exit Vietnam and re-enter from Cambodia, Laos or China, you will need a three-month multiple-entry visa.

How to apply visa to Vietnam?

++ Obtain Visa from your home country

• You have to submit: Passport with at least 6 months validity, Visa application forms, required by Vietnamese embassy or consulates in your country and a fee. 
• You can download the Application Form here for UK citizens, US citizens and Australian citizens.
• Visa forms are available after 4-5 working days by getting directly or by mail with a stamped, self-addressed envelope addressed to their Visa section. Request by email is perhaps acceptable (in some cases).

++ Visa Exemption List

• Nationals of Thailand, Indonesia, Malaysia, Singapore, Laos, Cambodia are permitted to stay for less than 30 days.
• Nationals of Phillipines are permitted to stay for less than 21 days.
• Nationals of Brunei are permitted to stay for less than 14 days.
• Nationals of South Korea, Japan, Sweden, Denmark, Norway, Finland, Russia are permitted to stay for less than 15 days.
• Nationals of Chile who hold a valid diplomatic or official passport are permitted to stay for less than 60 days.
• Nationals who hold APEC Business Travel Card from Asia-Pacific Economic Cooperation (APEC) member economies are permitted to stay for less than 60 days.

Update June 2015: Vietnam State has just decided one-way waiving Visa for those countries UK, France, Germany, Italy and Spain for stay less than 15 days. The waive valids from July 1, 2015 to June 2016.
You can look up for your country and passport qualified for exemption at Full List by Vietnam Diplomatic Office here

Custom Regulations and Declarations

Arriving in Vietnam, all visitors must fill in  declaration forms and show their luggage to Customs Officials upon request. There are no limited amounts of foreign currency, objects made of gold, silver, precious metals and gemstones or plated with silver or gold but visitors must declare these in detail on the customs forms.

++ Luggage of Prohibited and Restricted carriage

• Following materials are prohibited accompanying baggage: corrosive, gas, explosive, toxic, oxygen, radioactive, flammable...
• Following materials are not permitted accompanying baggage: knife, scissors, gun, cartridge, wheelchair with battery;
• Passenger should not put money, jewel, document, important samples... in your baggage. Baggage should be covered and locked carefully;
• Passenger should not put breakable materials such as china, electronic, bottle, jar... inside your baggage;
• Following goods are prohibited carrying in flight: fish sauce, durian...

++ Things allow to bring into Vietnam

• Tourists are authorized to bring in the following items duty-free: Cigarettes: 400 pieces; Cigars: 50-100; Tobacco: 100 gram; Liquor: 1.5l.
• Personal effects of a reasonable quantity
• Small gift items valued at not more than US$500.
• You are expected to declare:
• Cameras, camcorders and other electric equipments not for personal use
• Jewelry not for personal use;
• Currency over US$5,000 (There is no limit to the amounts of cash, precious metals and gems people can bring in, but amounts of over US$7,000 must be declared);
• Video tapes (they may be kept few days and screened).

++ Things allows to bring out of  Vietnam

• Goods of commercial nature and articles of high value require export permits issued by the Customs Office.
• Antiques, some precious stones and animals listed in Vietnam's red-book may not be brought out of the country.
• Money: below US$5,000 of cash.