Transatlantic travelers must remember that the US Electronic System for Travel Authorization (ESTA) did go live in January, replacing the old visa-waiver forms handed out to arriving passengers.
Instead, all passengers heading for or transiting through America must apply online for permission to travel at VISA APPLICATION
Registration is free and authorisation, which lasts for two years, is usually granted while you wait, although the US embassy advises applying no later than 72 hours before departure in case of complications.
On January 12 2009, the green form was replaced by an electronic system, which will require travellers to fill in a form before they fly.
The Electronic System for Travel Authorization (ESTA) forms are available online at VISA APPLICATION
Travellers who do not fill in the forms will be barred from boarding an aircraft or vessel bound for the US.
The form requires similar information to that requested by the old green form: details of criminal records, communicable diseases, history of visa revocation or deportation and personal details such as name, birth date and passport number.
The US authorities say the new system is simpler: Once filled in, the data is kept on record for two years, so subsequent visits within that time do not require more online form filling.
It is also intended also tighten security: "Getting this information in advance enables our front-line personnel to determine whether a visa-free traveler presents a threat before boarding an aircraft or arriving on our shores," said Homeland Security Secretary Michael Chertoff.
The new system applies to all travellers visiting the US from the 27 countries that are signed up to the US visa waiver programme. Those travellers without internet access should ask their travel agent to fill in the form under their instruction.