Form I-94 is the Entry / Exit Record for foreigners who are admitted to the United States by means of any visa. In general, a Custom and Border Patrol (CBP) officer stamps the passport informing the foreigner the period of time in which he is authorized to be in the United States without interruption. The visitor must leave the US on or before the departure date stamped on the stamp. This can also be verified online based on the passport number and name of the admitted foreigner. The Form I-94 number is also known as the Exit Number or Admission Record Number.