There's more than one way to get there...
Generally speaking, there are two different approaches to studying abroad. One is to use a program provider – any third party that facilitates admission to a foreign university, helps with housing, offers orientation programming and perhaps some cultural programming, and makes sure that credit transfers back to the U.S. Think of the University of Iowa as a program provider. The second approach is for the student to apply directly to the foreign university. There are pros and cons to both strategies.
Using a program may cost more than independent enrollment, because of the higher level of student services provided (see above paragraph). On the other hand, sometimes program providers receive tuition reductions because of the volume of students going to a particular university; and those tuition reductions can be passed on to the student.
Some program providers essentially set up American-style classrooms at locations overseas, and house all study abroad students together in private apartments or in a building owned by the provider. This results in less cultural immersion than might be desirable.
Applying directly to a foreign university as a non-degree, “visiting” student can result in some cost savings and usually guarantees a high level of cultural immersion because the student is taking classes that any other degree-seeking student at the institution is taking, and usually lives in dormitories with host-nationals and other international students.
Students who rely on U.S. federal financial aid to study abroad are sometimes unable to use their aid when applying directly to a foreign university.
In short, applying directly to a British university has certain advantages (a cost-savings, mainly) and some challenges. It is best to compare the pros and cons of using a provider to independent enrollment and talk to a study abroad advisor in the Study Abroad office before making a decision about which approach is right for you.
Direct Enrollment in On-Going Classes at British Universities