There sometimes seems to be some confusing information about what is needed to enter the US. It is really quite simple, but let´s once for all clear it out.
First, to enter the US, you need an official permit (more about that later). This is something you must arrange with in your home country before you start your travel. You can never – for any reason – come to the US border and think you can arrange with that, standing at the border control. You will be sent back to your port of departure, instantly. Period.
There are two types of permit: the VISA and the ESTA. Let us start with the basic one, the VISA. A US VISA allows you to travel to a port of entry and request permission to enter the US. If you are allowed into the country, you may freely travel around, under certain conditions. You are not allowed to be engaged in any commercial activities, you cannot work and you are only allowed to stay in the country in a max total of six months during a calendar year. The VISA as a such, is generally valid for 5 years or less.
And here we sometimes have misunderstandings. The VISA doesn´t automatically grants you permit to enter the US soil. It only means that a consular officer at a U.S. Embassy or Consulate somewhere in the world has determined you are eligible to seek entry for a specific purpose. But it is the stern gentleman in front of you at the border control, the DHS (Department of Homeland Security) inspector, who is responsible for admission of travelers to the United States, for a specified status and period of time.
To apply for a VISA is a little bit complicated: it takes time, it may cost you some money and you have to visit an US representation in your home country for an interview. And if you only intend to visit the US for a shorter time as a tourist or so, the ESTA (Electronic System for Travel Authorization) was created. You can say, the ESTA is a more simple type of a VISA. It is totally electronic as to the handling. You do it all over internet and get a confirmation within 30 minutes or so. It allows you to stay in the US for three months (90 days) in a calendar year, it is valid for 24 months and it will cost you USD 14.00. That is all.
There are internet sites who offer you to do this for you. They are not in any way illegal, but they do exactly the same thing you can do yourself, they charge you some USD 50.00 or USD 60.00, pay the USD 14.00 and keep the balance for themselves. You can do a lot of better things for these USD 45.00…