What an ESTA is, and above all what it is not
ESTA (Electronic System for Travel Authorization) is an automated system run by CBP, the United States customs and border protection agency, that determines whether you are eligible to travel to the country under the Visa Waiver Program (VWP) and whether your travel poses any law enforcement or security risk.
It is worth nailing down from the start the two things an ESTA is not, because nearly every serious problem comes from confusing them.
It is not a visa. CBP puts it plainly: an approved ESTA is not a visa, and it does not meet the legal or regulatory requirements to serve in lieu of a US visa where a visa is required. If your trip does not fit what the VWP allows, short-term tourism or business, an ESTA is of no use to you: you need the relevant visa.
It does not guarantee entry. An ESTA authorises you to board a carrier bound for the United States; who decides whether you enter is the immigration officer at the port of entry. CBP itself warns that a VWP traveller without an approved ESTA may be denied boarding, face delayed processing, or be refused admission at a US port of entry outright.
Who needs one
All eligible nationals or citizens of VWP countries who plan to travel to the United States for business or pleasure under that programme are required to obtain an authorisation through ESTA. That includes minors, whether or not they are travelling with an adult: there is no exemption by age, and a three-month-old baby needs one just as much as an adult does.
The requirement applies to anyone arriving by air or sea regardless of their country of origination or port of embarkation. In other words: flying to the United States from a third country rather than your own does not release you from the ESTA.
One case that catches many people out: transit counts too. The United States has no visa-free transit and no international zone to wait in, so even if you are only changing planes you must clear immigration and customs, and you need an ESTA or a visa exactly like someone entering the country.
What it costs and how far ahead to apply
The ESTA fee rose from 21 to 40 dollars. It is a relatively recent change that has yet to reach many third-party pages, so if you come across the old figure, that page is out of date.
On timing, CBP recommends that first-time applicants apply at least 72 hours before travel, to allow time for processing. Leaving it to the day before is one of the costliest and most avoidable mistakes on this list: most applications clear in minutes, but the ones flagged for manual review do not, and without an approved ESTA the airline will not let you board.
How long it lasts and when you need a new one
An approved ESTA is valid for two years, or until your passport expires, whichever comes first. That “whichever comes first” matters: if you renew your passport after eight months, your ESTA dies with the old passport even though it had more than a year left on it.
You must apply for a new authorisation when:
- your passport information changes, and CBP is explicit here: if a traveller’s passport information changes, the individual is required to apply for a new travel authorisation through ESTA;
- you change your name;
- you change your citizenship;
- any of your answers to the eligibility questions change.
That last one is the most commonly overlooked. The eligibility questions cover criminal history, certain illnesses, arrests and particular travel histories; if your circumstances change after you obtain the ESTA, the authorisation you hold no longer reflects reality and has to be redone.
If it is refused
If your application is refused and you still want to travel, the route is to apply for a nonimmigrant visa at a US embassy or consulate. There is no fast-track appeal that reverses an ESTA refusal.
And there is something worth knowing in advance so as not to waste time: CBP does not explain the reasons for a refusal. You will not receive a breakdown of which answer or which record triggered it. This is not a glitch, nor something you can overturn by reapplying persistently; it is how the system works. The productive move is to go straight to the visa process, which is a procedure with an interview where your situation is examined individually.
The mistakes that leave people at the gate
Using a website that is not the official one. The application is made on CBP’s official site. Numerous intermediaries charge a mark-up to fill in the very same form, and some are outright fraudulent. If the site you are looking at is not CBP’s official portal, it is not the ESTA: it is someone selling you the paperwork.
Applying the day before. As above: at least 72 hours ahead, on CBP’s own recommendation.
Renewing the passport and forgetting the ESTA. This is probably the most frequent slip among frequent travellers, precisely because anyone who already holds an ESTA assumes they have two years in hand.
Believing it authorises work or study. The VWP covers short-term tourism and business. Other purposes require a visa.
Confusing authorisation with entry. We repeat it because it is the costliest misunderstanding: an ESTA lets you board, not enter. The decision belongs to the border officer.
VWP eligibility restrictions
There is a block of restrictions worth checking before assuming you are eligible: the Visa Waiver Program Improvement and Terrorist Travel Prevention Act of 2015 limits access to the programme for people with certain travel histories and for certain dual nationality cases. The precise conditions and the list of countries concerned are maintained by CBP itself in a dedicated FAQ section on that Act, and that is where they should be checked: they are the details that change most often, and there is no sense reproducing a list here that may go stale.
If you think you may be affected, the prudent course is to assume you will need a visa and start that process early, rather than finding out when the ESTA comes back refused.
What to do if you are only passing through
If the United States is merely a stopover, see our explanation of the differences between a visa, an e-Visa and an electronic authorisation and keep the point above in mind: there is no visa-free transit. Changing planes at a US airport means formally entering the country, with everything that entails: immigration control, customs, and collecting and re-checking your baggage.
Guide verified on 13/09/2026. Sources: U.S. Customs and Border Protection, “Electronic System for Travel Authorization” and “Frequently Asked Questions about the Visa Waiver Program (VWP) and the Electronic System for Travel Authorization (ESTA)” (the nature of an ESTA, the requirement for VWP nationals including minors, two-year validity or until passport expiry, the circumstances requiring a new authorisation, the consequences of travelling without an approved ESTA); CBP, “CBP Announces ESTA Fee Change” (fee increase from 21 to 40 dollars); CBP, “CBP Reminds Travelers to Allow 72 Hours for ESTA” (recommended lead time); CBP help article on ESTA denials (reasons are not disclosed); CBP, “Visa Waiver Program Improvement and Terrorist Travel Prevention Act Frequently Asked Questions” (eligibility restrictions by travel history and dual nationality).