US Immigration Visas : Non Immigrant Visas
There are many non-immigrant visa categories and each is identified by an alphabetical designation. They are generally issued for specific purposes such as study, holiday, business, employment, investment, or diplomatic need. Travelers can sometimes quickly obtain non-immigrant visas, as there are no quotas. These visas generally come with different privileges.
All non-U.S. citizens who enter the United States on non-immigrant visas are considered to be there temporarily. If you are there on a temporary non-immigrant visa and apply for an immigrant visa, you are normally deemed to have "lost" your intent to stay there temporarily. So long as you are in the U.S. and do not need to renew your temporary visa for some time, this change of intent should not a problem. However, if you intend to travel outside the U.S. you could have problems, e.g. you may not be allowed back in.
There are only a few non-immigrant categories that allow a person to have “dual intent”, that is, to intend to be in the U.S. temporarily but with the intent to emigrate. In these categories, international travel and extensions of stay are possible, but limitations exist. The most common dual-intent visas are the H, L, and E visas.
A visitors visa is required of U.K citizens who wish to visit the U.S. for a period of less than six months but more than the 90 days permitted under the visa waiver program (VWP), or where they are not eligible for the VWP program. These include the B1 and B2 visas.
An employment based visa is required where U.K. citizens are sponsored by a U.S. employer wish to work in the U.S. based on a specific non-permanent job offer. These include the H-1b and L-1 visas.
An investment based visa may allow a U.K. investor as well as essential employees to enter the U.S. for the purpose of developing a business and remain so long as said business continues to operate. These include the E1 and E2 visas and, in some instances, the L-1 visas
OTHER NON-IMMIGRANT VISAS
A/G Representatives of foreign government
C Transit visa
D Crewman
F Students: in academic or language programs
H Temporary Workers: and trainees
H-1A: Registered Nurse
H-1B1: Specialty Occupation (Professionals)
H-1B2: US Department of Defence special visas
H-1B3: Artists, entertainers or fashion models of national or international acclaim
H-1B4: Artists or Entertainers in unique or traditional art form
H-1B5: Athletes H-1BS: Essential support personnel for
H-1B entertainer or athlete. I Journalists J Exchange visitors
K Fianceé: of U.S. citizens
M Students: in vocational or other non academic programs
N The parents of certain special immigrants
O Temporary Workers of extraordinary ability
P Athletes & Entertainers
Q Cultural exchange visitor
R Religious: Visas