Vietnam Visa
Basic Requirements 
A Vietnam visa is part of the required migration process for all travellers to the country. Dependent on the purpose of an applicant’s visit, a Tourist or Business visa will be required for entry.
You can apply for your visa up to 3 months before your intended arrival date.
Processing Times
When applying for a Vietnam visa, processing time and fees are very dependent on the visa class, as well as the nationality of the applicant and the time of year.  Both the time taken to process the visa application and the cost are subject to change, but by having an understanding of each Vietnam visa class and seeking professional assistance when making an application, you can be assured the most time and cost efficient process possible.
Temporary Vietnam Visas
Vietnam Tourist Visa 
A Vietnam tourist visa is issued only to applicants entering the country for the purpose of tourism, or for a private visit.  The initial duration of the visa is one month, although this can be extended by an additional month, if required.
An application for a Vietnam tourist visa requires that the applicant submit a valid passport, as well as a separate passport-sized photograph, a correctly completed application form and the requisite fee.
The Vietnam tourist visa is granted on the basis that the holder return to their country of residence upon the expirty of the visa, and not engage in employment while residing in Vietnam.
Vietnam Business Visa  
A Vietnam business visas may be issued for a validity ranging from one month to one year, but this is dependent on the purpose and proposed duration of the trip. Generally, most Vietnam business visas are issued for a duration of six months.
The Vietnam business visa grants holders the right to attend meetings, conferences and other business-related activities.  However, the holder is not permitted to be employed in any capacity during their time in Vietnam.
nAn application for a Vietnam business visa requires that the applicant submit a valid passport, as well as a separate passport-sized photograph, a correctly completed application form and the requisite fee. Additionally, should the applicant be applying for a multiple entry business visa, their application must be approved prior to their arrival by the Immigration Department in Vietnam.
Vietnam Embassy Information
Embassy of Vietnam
12 Victoria Road
London
W8 5RD

Telephone:  020 7937 1912
Fax:  020 7937 6108
Website:  www.vietnamembassy.org.uk/consular.html  Source: visabureau.com