Originally Posted by
Geordie405
TSA has access to the airlines' manifests so you need to be flying to get through TSA but you only need to present your BP at the gate when boarding.
Though if you’ve changed your booking within 24hrs of departure, there’s a high risk it might not have re-synced and you’ll need a BP (and TSA supervisor) to pass you through. Not something I’d be taking a chance on if planning to arrive late at the airport.