Originally Posted by
LucasD81
Are you a US citizen or did you have show any evidence that you are allowed into the US?
Of course they are verifying that you are a US Citizen, LPR, or otherwise authorized traveler at check-in, and again when accessing the boarding area at LHR. And of course your info is transmitted to CBP. Do you really think they're going to let an unauthorized traveler slip by in violation of the existing travel restrictions to the USA?