Do you have a connecting flight in the USA? Then you always have to apply for an ESTA, except if you possess an American passport or US visa. Even if you do not leave the airport in the USA during the layover period, you are still required to possess an ESTA. You can only apply for this travel authorization before departure. As early as during check-in at your initial flight, you will be checked for a valid travel permit, based on your passport number.
Transfer or Transit
There is a difference between transferring to another flight and making a transit through the USA. A transfer is commonly understood as: leaving the plane with which you arrived in the USA and boarding another plane to continue your journey to another country. A transit is understood as: not leaving the plane with which you arrived in the USA; you stay inside the cabin until you can continue flying to another country on the same plane. Transit flights through the USA generally have the purpose of refueling the plane, but are becoming less frequent. Both with transferring flights and transit flights through the USA, you are required to possess a valid ESTA.
To change flights in the USA, an ESTA is required
Leaving the airport in-between
Many travellers experience extended layovers as they transfer between flights. It is possible to leave the airport during this period, provided the traveller has a valid ESTA. It doesn’t matter if you leave the airport or how long you remain outside it. The only restriction is that you cannot stay in the USA for longer than 90 days (otherwise you need a visa).
How do I acquire an ESTA for connecting flights?
The requirements and procedure for applying for an ESTA for a connecting flight or a transit are the same as that of the regular variant. You can make use of the general application form. Here, you can declare that you are only traveling to the USA for a connecting flight or a transit. The questions that are usually asked regarding subjects such as place to stay in the USA will disappear when the applicant indicates that they will not be staying in the USA.
Do I need a new ESTA for each transit?
It is not necessary to file for a new ESTA for each individual flight transit in the USA. The ESTA, if granted, is valid for two years and allows for an unlimited number of trips to or through the USA. So even if the purpose of the first trip is for tourism and the second one is for business, or if you use the first ESTA only to transfer flights in the USA, it is not necessary to apply for a new ESTA if you return to the US, as long as the previous one has not expired. Take note: should the passport with which the ESTA has been applied for expire within this period of two years, the ESTA will also expire earlier. Read more about the validity of the ESTA.Apply for your transit ESTA now