Generally speaking, all persons traveling to the United States will need a U.S. visa. The only exception are those travelers who qualify for visa-free entry under the Visa Waiver Program (VWP), which allows certain nationals to stay up to 90 days without the need for prior application for a visa.
ESTA stands for Electronic System For Travel Authorization. The electronic system is run by the Department of Homeland Security DHS and is mandatory for everybody who wnats to travel visa-free under the Visa Waiver Program VWP.
However, entry is not granted without satisfying preconditions. In other words, not all stay purposes are allowed under the Visa Waiver Program. People who use the VWP may only enter the U.S. for tourist (tourist visa waiver) or limited business purposes (business visa waiver).
The Visa Waiver Program allows visa-free entry to the entire territory of the United States and Puerto Rico, Guam, and the U.S. Virgin Islands.
Travelers may only enter on a private plane or private boat with a valid visa.
Currently citizens of the following 38 countries qualify for the Visa Waiver Program:
(as of 04/01/2019)
VWP travelers need a valid passport (electronic passport) in accordance with the current regulations of the U.S. authorities. In any case on, we advise you to research information on the website of the U.S. embassy in your country about the exact passport regulations. Generally speaking, your passport should have at least six months left of validity from the date of your intended departure from the United States. The so-called Six Month Club is an exception to this rule: citizens of certain countries within the VWP (including Germany, Austria, and Switzerland) only need a passport that will remain valid for the duration of the intended stay.
Travelers taking advantage of the VWP also require a return ticket or onward ticket that may not end in Canada, Mexico or the Caribbean.
Certain groups of people are categorically banned from participating in the visa-free travel program:
These designated groups of people must apply for a visa for entry into the U.S. In individual cases, the affected person may submit an application for exemption (= waiver).
Everyone who would like to travel to U.S. under the VWP must use the Electronic System For Travel Authorization (ESTA). Travelers must obtain the so-called ESTA authorization prior to travel by air or sea.
The ESTA application is only available online and can be completed at any time, even if you do not yet know you travel dates. You can apply for your ESTA travel authorization at https://esta.cbp.dhs.gov. It is recommended that you complete the application in a timely manner, and no later than 72 hours before departure. A fee of 14 U.S. dollars per person will be charged, which can be paid by credit card, debit card, or the PayPal online payment system.
The ESTA is valid for two years or until the expiration of the passport (if this occurs first) from the date of issue (not from the date of first entry) if you are approved. It is valid for multiple entries.
ESTA approvals can be applied not only to individuals but also to groups (e.g., tour groups or families).
If the ESTA application is denied, the traveler cannot use the VWP, i.e, they must apply for a visa at a local U.S. consulate in their home country.
The ESTA application must include information about the
If incorrect information about the passport or personal data have been submitted, then a new ESTA application must be completed in order to correct the information.
The previously required I-94W form has been deprecated by the ESTA process, and now it only needs to be completed for entries over land. When leaving the country the traveler is required to submit this document, and the timely departure must also be documented.
The Visa Waiver Program allows travelers a maximum stay of up to 90 days per entry. This period is not a legal right: The border officers will decide whether the person is allowed entry and will note the allowed period in the passport. Additionally, the residence status of travelers visiting the United States under the Visa Waiver Program is stored online in the I-94 form, thus recorded electronically in the system of the U.S. authorities.
Extensions of the VWP period of stay in the United States are generally not permitted, not even if the traveler exits the country (to Mexico or Canada, for example) and then reenters the U.S.
The most important information about this visa category can also be found here, briefly summarized and free to download in PDF format.