Originally Posted by
KLouis
the ESTA # of Europeans travelling to the US is also transmitted to the American authorities by the airline and not by the "exit immigration". So nothing new/impossible/difficult here!
No they don't Airlines don't know my ESTA number. There is no field in APIS to enter it for example.
Airlines transmit the passport number to the US (along with other demographic data) and they get sent back a marker that shows them you have an ESTA which then along with the passport check generates the 'docs ok' on the boarding pass.