British Nationals with a valid passport can visit the US for business or pleasure without a visa for up to 90 days per year. Travelers wishing to use the Visa Waiver are required to register themselves online on the Electronic System for Travel Authorization (ESTA) before departure for the US. This should be completed at least 72 hours before departure and it is valid for multiple entries into the US for up to 2 years.
For those wishing to stay between 90 days and six months, you must apply for and hold a B2 visa prior to entry. This visa requires proof that the applicant has sufficient funds to support themselves during their stay in the USA, for up to 6 months.
Some Brits may be looking to reside in Florida and the immigration laws in the USA are strictly enforced. Those seeking a US Green Card, which entitles them to live and work in the state, face close scrutiny by the Immigration and Naturalization Service, particularly if they wish to start a business. Persons who are planning not to work or retire, must be able to demonstrate substantial means to support themselves. This can be a major obstacle for those who seek the dream of retiring to Florida.
It is advised that all persons looking to reside in the USA, working or not, should obtain professional advice on US Immigration through an immigration lawyer.