A waybill number is a unique identification number assigned to a shipment that contains all the information that the relevant authorities need to know about its point of origin, its contents, where it is headed, and the route it will take. The waybill is usually attached to the exterior of the package and is used by couriers, customs officials, and machines to easily identify and track the package. The DHL Express air waybill is a vital document containing all the requisite information about a shipment such as the proof of ownership or recipient details needed for shipping. The waybill number is also known as the AWB number, which is a unique 10-digit code that acts as the reference for the shipment in the event that you need to track it.