If you are traveling to the United States under the Visa Waiver Program you require an electronic passport. Machine-readable passports are no longer accepted for travel. Click here for further information. The failure to determine that your passport qualifies for the VWP may result in you being denied boarding by the airline..
U.K. Passport Holders
United Kingdom Passport holders please note: A passport indicating that the bearer is a British Subject, British Dependent Territories Citizen, British Overseas Citizen, British National (Overseas) Citizen, or British Protected Person does not qualify for travel without a visa. A passport which states holder has Right of Abode or indefinite leave to remain in the United Kingdom does not qualify for visa free travel;
Passport Validity
With the exception of passport holders of Brunei the requirement that a passport be valid for six months beyond the holders stay in the United States is waived. If your passport is valid for less than 90 days, you will be admitted into the United States until the date on which the passport expires. Note: Citizens of Brunei are not covered by this ruling and must be in possession of passports valid for at least six months from the date on which they depart the United States, regardless of their proposed length of stay.