Originally Posted by
nmh1204
Americans can enter the UK free of charge, we get charged to enter America lol
But Americans (and everyone else) get charged quite handsomely to
leave the UK.
OP will be asked to provide his full address whilst staying in country on the landing card he fills out en route and presents at border control. Other than that, his passport, and proof of funds and plans to leave, he ought to be fine.