National Motor Freight Classification (NMFC) is the freight classification system that was created by the National Motor Freight Traffic Association (NMFTA) and is used for all interstate, intrastate, and foreign commerce movement of LTL cargo. NMFC codes provide standardized freight classes to determine the transportability of most of the countless different commodities that are shipped together in LTL shipments each year.
CWT stands for hundredweight. LTL shipments are priced “per 100 pounds,” “cwt,” or “per hundredweight.” This means that a 400 lb shipment priced at $25 CWT would cost $100, not including accessories or specialty services.
If you don't include an NMFC code on your BOL, it is very likely that your carrier will charge you a reclassification fee and charge you the cost of shipping the freight they they determine your shipment is.