If you love traveling but can’t stand the long customs lines, then it might be worth it for you to get a Known Traveler Number (KTN). A KTN is a number that’s issued by either the US Transportation Security Administration (TSA), Department of Homeland Security (DHS) or Department of Defense (DoD). This number indicates that the person who has it has undergone a pre-flight background check before checking in for their flight and is eligible for an expedited customs experience. To get a KTN, apply for TSA Precheck, Global Entry, NEXUS, or SENTRI.