An enroute status is given to a shipment upon initial entry into the United States.This status indicates that the in-bond has been accepted by CBP and is currently in transit to its destination. 

It can also be given immediately after the creation of the in-bond if it is for a foreign trade zone withdrawal or a bonded warehouse. According to regulations, these in-bond shipments need to be at their destination in no more than 30 days or else they will be declared overdue.