Immigration Q & A: I-94W departure card query
(APIS, or Advance Passenger Information System, is an electronic mechanism created by CBP for airlines to provide immediate passenger information to the agency.)
If you did not overstay your visa waiver you should not have a problem returning to the U.S. And, it has to be said, overstays have also returned because of the aforementioned lack of a virtually foolproof system to record departure information.
CBP allows for those who did not submit the I-94 when leaving to do so via mail if they choose. Because of space restrictions we’ll explain more about this process next week.