According to the U.K. Border Agency, American citizens do not need to obtain a visa to visit the United Kingdom unless you intend to stay in the U.K. longer than six months and cannot prove that you have enough funds to sustain the duration of the visit or an onward plane ticket. If staying for longer than six months, U.S. citizens will need to apply for the appropriate visa in advance of the trip.
Applications for all the different types of visas can be found on the U.K. Border Agency website. In fact, citizens of the United States must complete the application and the scheduling of an appointment for a visa online. You will need a valid e-mail address, the address of where you will be staying in the U.K. and your itinerary in order to apply online.
You will need to schedule an appointment at the appropriate visa office. There are offices in New York City, Chicago and Los Angeles. Each office handles specific states, so you will need to check online at www.visainfoservices.com for the states that the office closest to you handles.
Along with your completed application, you will need your passport and two identical color visa photographs. It also is required to submit two fingerprints to be placed on a biometric chip that is embedded in the visa document. In some cases, you will need student identification or other documentation that proves the reason for your extended stay in the United Kingdom.
The time for determination of whether to issue you a British visa in the United States averages about 10 to 15 days. Once you have been approved for the visa, you will receive the visa documents in about 15 to 30 days. You will need the visa before you enter the United Kingdom as visas are not issued at U.K. airports.