An NMFC (National Motor Freight Classification) code is a standardized classification system used by domestic freight carriers in the United States to categorize less-than-truckload (LTL) shipments for pricing purposes. Published by the National Motor Freight Traffic Association (NMFTA), NMFC codes assign freight classes based on a product's density, stowability, handling requirements, and liability characteristics. NMFC codes are entirely separate from HTS codes used for customs classification.
Why It Matters for Importers
Importers frequently confuse NMFC codes with HTS codes because both involve classifying products with numeric codes. However, they serve completely different purposes. An HTS code determines your customs duty rate and is used by CBP. An NMFC code determines your domestic freight shipping rate and is used by trucking companies. Using the wrong code in the wrong context causes problems in both directions.
When your imported goods arrive at a U.S. port and need to be transported by LTL freight to your warehouse, the NMFC code determines the freight class and price. An incorrect NMFC classification can result in reclassification fees, freight invoice adjustments, or refused pickup by the carrier.
Key Details
- NMFC codes are typically 5-6 digits and map to 18 freight classes ranging from Class 50 (lowest cost, dense/easy-to-handle goods) to Class 500 (highest cost, low-density/difficult goods).
- The four factors that determine NMFC classification are density (weight per cubic foot), stowability (how easily the item is stored with other freight), handling (special requirements), and liability (value and fragility).
- NMFC codes are maintained by NMFTA and updated regularly. The database is not freely available — it requires a subscription or access through your freight carrier.
- Full truckload (FTL) shipments typically do not require NMFC codes, as pricing is based on origin, destination, and equipment type rather than commodity classification.
NMFC vs. HTS: A Quick Comparison
HTS codes govern what you pay the government in duties. NMFC codes govern what you pay the trucking company in freight. Your customs broker handles HTS classification. Your freight forwarder or carrier handles NMFC classification. Both are important to your landed cost, but they operate in entirely different systems.
For more on how customs brokerage and freight forwarding differ, see our guide on customs broker vs. freight forwarder.