NMFC & Freight Class Explained 

By Rubi Rodriguez

Published on February 25, 2026

In short

Less-than-truckload (LTL) shipping still runs on a single number: freight class. Get that number wrong and you risk re-class fees, billing disputes and delayed pickups. Below is a plain-language look at how the National Motor Freight Classification (NMFC) works today, what changed in the big 2025 overhaul, and how Lazr automates the hard parts. Why…

News

Less-than-truckload (LTL) shipping still runs on a single number: freight class. Get that number wrong and you risk re-class fees, billing disputes and delayed pickups. Below is a plain-language look at how the National Motor Freight Classification (NMFC) works today, what changed in the big 2025 overhaul, and how Lazr automates the hard parts.

Why freight class matters

Carriers quote and invoice LTL moves in hundred-weight (CWT) rates tied directly to freight class. A lower class (say 50) is denser, easier to load and cheaper per lb; a higher class (up to 500) is bulkier, fragile or high-risk and commands a premium. The NMFC historically used 18 classes, from 50 to 500 .

Getting the class right avoids:

  • surprise re-weighs and accessorials
  • charge-backs from 3PLs or end customers
  • carrier blacklisting for chronic mis-classing

The four classic factors

1. Density : weight ÷ cubic feet

2. Stowability : odd shapes or hazmat reduce stackability

3. Handling : fragility, need for side-door or lift-gate

4. Liability : theft risk or high value

2025: density takes the wheel

On 19 July 2025 the NMFTA replaced much of the commodity-based table with a 13-tier density scale, adding new Classes 50 and 55 for very dense freight . More than 2,000 commodities shifted to density rules, making mis-classing both easier and costlier .

Common pitfalls we still see

  • Listing nominal rather than packed dimensions
  • Forgetting pallet height in stackable freight
  • Using last year’s class after product redesign
  • Rounding density up or down “a little” to hit a nicer rate

How Lazr removes the guesswork

  • Automatic class calculation – Enter length, width, height, weight; Lazr returns the correct NMFC density class instantly.
  • Pricing Intelligence – compares that class across 100 + connected LTL carriers so you see the cheapest on-time option in one screen.
  • Real-time API/EDI tariffs – mean your quote already reflects the 2025 scale—no manual look-ups.
  • All shipment data – stays centralised for audits, so finance can trace every re-weigh or credit note in seconds.

How Lazr Supports Successful Cross-Border LTL Operations:

  • All docs in one place –Bills of Lading and shipping labels are generated within the platform, while documents such as CUSMA certificates and other supporting files can be uploaded to the order for easy access and visibility.
  • Pricing Intelligence – Compares API, EDI and paper tariffs to find the most cost-effective compliant carrier on every lane.
  • Shipment visibility & tracking – Manage all your shipments in a single TMS to monitor progress, support follow-ups, and maintain end-to-end traceability.
  • Trilingual human support – Work with a Canada-based operations team offering shipment support in English, French, and Spanish.

Key takeaways

  • Freight class still drives every LTL dollar, density matters more than ever.
  • The 2025 NMFC update created finer break-points; double-check your density math.
  • Automating class selection inside your TMS eliminates human error and costly re-classes.

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