Known shipper is a shipper status determined by the TSA (Transportation Security Administration). A shipper must be a known shipper in order to load cargo on a passenger aircraft from the US. TSA’s Known Shipper Management System confirms the validity and integrity of the shipper to establish the shipper as a known shipper.
Known shippers also have better freight rates, more route options, and fewer delays as a result of being an established shipper with the TSA.
Cargo Programs - TSA