# What is NMFC? A Complete Guide to Freight Classification

Source: https://freightapis.dev/learn/what-is-nmfc · Updated: 2026-10-09 · Publisher: FreightAPIs

NMFC - the **National Motor Freight Classification** - is the standardized system used to categorize less-than-truckload (LTL) freight in the United States. Every commodity that ships by LTL is assigned an NMFC item number and a freight class, and together they determine how carriers price and handle the shipment.

## What does NMFC stand for?

NMFC stands for **National Motor Freight Classification**. It is published and maintained by the National Motor Freight Traffic Association (NMFTA), a non-profit membership organization of motor carriers. The classification is the LTL industry's common language: it lets a shipper in one state and a carrier in another agree on exactly what is being shipped and how it should be rated, without ambiguity.

Each entry in the classification has an **NMFC item number** (for example, item 156600 for furniture) and an assigned **freight class**. Many items also have sub-provisions that assign different classes depending on the commodity's density.

## How does NMFC classification work?

The classification groups commodities by four transportation characteristics:

- **Density** - weight per cubic foot. Dense freight is cheaper to ship per pound because it uses less trailer space relative to its weight.
- **Stowability** - how easily the item loads alongside other freight. Oversized, hazardous, or oddly shaped items stow poorly.
- **Handling** - the effort and care required to load and move it.
- **Liability** - risk of damage, theft, or damage to adjacent freight, plus the commodity's value.

Based on these factors, every commodity falls into one of **18 freight classes**, ranging from class 50 (the densest, cheapest freight) to class 500 (light, bulky, fragile, or high-value freight). See [Freight Class Explained](https://freightapis.dev/learn/freight-class-explained) for the full list.

## Why NMFC codes matter

Using the correct NMFC code is not optional bookkeeping - it directly affects cost and compliance:

- **Accurate pricing.** The class drives the base rate. The wrong class means an over- or under-quoted shipment.
- **Avoiding reclassification fees.** If a carrier inspects a shipment and finds the class wrong, they reclassify it and bill the difference, often with a penalty.
- **Fewer billing disputes.** A correct, documented NMFC code on the bill of lading is your defense if a charge is questioned.

## NMFC vs. freight class - what is the difference?

People often use the terms interchangeably, but they are not the same. The **NMFC item number** identifies the *commodity* (what you are shipping). The **freight class** is the *rating category* (50-500) assigned to that commodity. One NMFC item can map to several classes through density-based sub-provisions - which is why two shipments of the "same" product can be rated differently if their density differs.

## FAQ

### Is NMFC the same as freight class?

No. The NMFC item number identifies the commodity; the freight class (50-500) is the rating category assigned to it. One NMFC item can have multiple classes based on density.

### Who maintains the NMFC?

The National Motor Freight Traffic Association (NMFTA), a non-profit organization of motor carriers.

### How many freight classes are there?

There are 18 freight classes, from class 50 (densest, cheapest) to class 500 (light, bulky, or high-value).

## Related guides

- [The Complete Guide to LTL Freight Classification](https://freightapis.dev/learn/complete-guide-to-ltl-freight-classification)
- [Freight Class Explained: All 18 NMFC Classes](https://freightapis.dev/learn/freight-class-explained)
- [How to Determine Freight Class: A Step-by-Step Guide](https://freightapis.dev/learn/how-to-determine-freight-class)
- [How LTL Shipping Works: A Beginner’s Guide](https://freightapis.dev/learn/how-ltl-shipping-works)