Individuals seeking admission to the United States in a nonimmigrant category must be inspected in person by an immigration officer at an official U.S. port of entry (POE). Before inspection, most arriving aliens are seen as "applicants for admission." Individuals also go through customs inspection at most ports of entry.
The U.S. Customs and Border Protection (CBP) Office of Field Operations (OFO) is responsible for determining the admissibility of travelers at U.S. ports of entry.
Non-U.S. citizens traveling to the United States may also download the free CBP One mobile app from the Apple App Store or Google Play and complete an electronic I-94 form up to seven days before their trip. The feature provides a more convenient way for travelers to apply for an I-94, review their past travel history, check their I-94 expiration date and obtain proof of their electronic I-94 from their mobile device. The I-94 is the record of arrival and departure issued to visiting or transiting persons to the United States except U.S. citizens, returning foreign visitors, foreign visitors with immigrant visas, and most Canadian citizens. Individuals who must prove their legal-visitor status to schools or universities can access their CBP arrival/departure record information from CBP One or the I-94 website.