What is an NMFC code?

The NMFC (National Motor Freight Classification) is a catalog maintained by the NMFTA that assigns most commodities a code and a freight class from 50 to 500. Carriers use the code on your bill of lading to price the shipment and to verify it was described honestly. Class reflects density, handling, stowability and liability — dense, durable freight gets low classes and cheap rates; light, bulky or fragile freight gets high classes.

Since the NMFTA's 2025 modernization, most commodities without special characteristics are classed on density alone, which you can estimate from dimensions and weight. Commodities with genuine handling or liability quirks keep their specific listings, so always confirm the code with the NMFC database or your carrier before booking — carriers reweigh and reclassify, and adjustment fees are steep.