Effective January 12, 2009, all passengers traveling to the U.S. by air or sea under the Visa Waiver Program (VWP) are required to get a valid ESTA approval in advance. You can not submit an ESA application at a U.S. port of entry or at a U.S. embassy or consulate.

Electronic System for Travel Authorization (ESTA) is a web based free, automated system made by the Department of Homeland Security to determine the eligibility of visitors to travel to the U.S. under the VWP. ESTA collects the same information as the paper I-94W form that VWP travelers fill out en route to the U.S.

As ESTA is required only for the citizens of VWP countries, citizens of Bermuda, Canada, the Marshall Islands, or Micronesia should not apply for it.

If you have not received ESTA approval, you may be denied boarding, experience delayed processing, or be denied admission at a U.S. port of entry.

All VWP travelers arriving into the U.S. by airplane or vessel require an approved ESTA, regardless of their country or origination or port of embarkation. Traveler entering the U.S. at land border ports entry can continue to be processed under the VWP and are not required to apply for ESTA authorization.

ESTA is required pursuant to Section 217 of the INA, as amended by Section 711 of the "Implementing Recommendations of the 9/11 Commission Act of 2007". It required DHS to develop and implement an automated system to determine, in advance of travel, the eligibility of visitors to travel the U.S. under the VWP and whether such travel posses a law enforcement or security risk. ESTA counterbalances vulnerabilities inherent in visa-free travel by establishing an additional layer of advance scrutiny that enables DHS frontline personnel to focus even more on the small population of potentially dangerous travelers.

Australia has a program called the Electronic Travel Authority, similar to ESTA of the U.S. Travelers to visit Australia may submit an application electronically through the Electronic Travel Authority web site. However, an ESTA is not a visa, unlike Australia's program.

Unless revoked, an ESTA authorization is generally valid for up to two years or until your passport expires, whichever comes first. And it is valid for multiple entries into the U.S.

However, this does not mean that you can stay in the U.S. for two years. You can only stay in the U.S. 90 days or less.

ESTA approval is not the same thing as a U.S. visa as it does not meet the legal or regulatory requirements to serve in lieu of a U.S. visa when a visa is required under U.S. law. Individuals traveling on valid visas are not required to apply for an ESTA.

ESTA approval just authorizes a traveler to board a carrier for travel to the U.S. under the VWP and is not a guarantee of admissibility to the U.S. at a port of entry. CBP officers make such determination in all cases at U.S. ports of entry or pre-clearance facilities.

You are not required to bring a paper printout of your ESTA approval with you when traveling. DHS communicates a traveler's ESTA status electronically to the carriers. However, you are highly recommended to take the print out anyway and bring it with you as sometimes airlines ask for it. Moreover, it also helps to maintain a record of your ESTA application number and to have confirmation of your ESTA status.

Even though ESTA application collects the same information as the Paper I-94W Form, during a transition period, you are still currently required to fill the Paper I-94W Form. You will be provided with the Paper I-94W Form en route to the U.S. or you can pick one up at the U.S. port of entry.

ESTA program will allow DHS to eventually eliminate this paper I-94W requirement when carriers are capable of receiving and validating messages pertaining to the traveler's ESTA status as part of the traveler's boarding status.

Even if you are just transiting through the United States en route to another country, you still need to apply for ESTA authorization if you are traveling under VWP. At the time of application, when you are asked for your "Address While In the United States", you should enter the words "In Transit", and your final destination location in the address lines.

If you are a citizen of the country that participates in the VWP and also a citizen of the country that does not participate in the VWP, you must apply for ESTA authorization using the VWP country's passport. If you are a citizen of two countries that participate in the VWP, you should apply for ESTA authorization using the passport that you would use to enter the U.S.

You can contact the CBP Customer Service Center at (703) 526-4200 or (877) 227-5511 for general questions regarding ESTA.

If you need to know the reason for your ESTA application denial or specific questions regarding your ESTA application, you must file a request with the DHS Redress Program.

Military Dependents from the Visa Waiver Countries are allowed to travel "space available" on military aircraft to the U.S. and may be admitted as visitors to the U.S. under the Visa Waiver Program.

VWP Military Dependents are required to have in their possession:

• A valid passport from their Visa Waiver Country.
  
  
• A Military Dependent Identification card issued by the U.S. Military Department of their sponsor, i.e., USMC, USAF, USN, US ARMY, US COAST GUARD.
  
  
• An approved travel authorization via the Electronic System for Travel Authorization (ESTA).
  
  

The Sponsor is not required to accompany them. The military dependent must not intend to immigrate while flying military "space available" aircraft.