Freight Class and NMFC Code Basics

Understanding NMFC codes: What LTL shippers need to know

National Motor Freight Classification (NMFC^®) codes are the backbone of freight classification, helping LTL shippers and carriers determine pricing and handling requirements. While the current system is well established by the National Motor Freight Traffic Association (NMFTA), updates are coming in 2025 that could impact how your freight is classified.  

Here’s a look at how NMFC codes work today — and what’s ahead.

What are NMFC Codes and freight classes?

The NMFC’s classification system is comprised of Freight Classes and NMFC Codes that categorize commodities within LTL shipments. The system currently uses thousands of items and subcategories to represent different shipping commodities. These classifications help determine the appropriate freight class for each item based on its shipping characteristics. There are 18 freight classes ranging from 50 to 500.

The NMFC items are organized as a list of commodity numbers with descriptions of the commodities. Some commodity numbers are extremely specific and only apply to a small range of items, while others are broad and refer to a variety of items. Each Commodity Number (and sub) has a specific class associated with it.

For example, printed spiral notebooks are currently categorized as NMFC Item 153760, Sub 03, Class 60.

Classification is based on each commodity’s transportation characteristics, considering four criteria:

1. Density. How much it weighs in relation to its size.

2. Handling requirements. How easy is handling, and does it require unique accommodations or care during transport?

3. Stowability. How easily is it loaded in the trailer with other freight? Is it heavy, oddly shaped, perishable, flammable or hazardous?

4. Liability. Does it present a liability issue like theft, damage or damage to other loads on the trailer? Are extra precautions required?

Class 50 has the lowest rates, while class 500 has the highest. Lower-class freight tends to be more dense, with little to no handling requirements, stability issues or liability concerns.

Upcoming changes to the system

This summer, the NMFC system is set to undergo significant updates. The biggest planned change is to migrate NMFC items that don’t have any special handling, stowability or liability requirements to a new 13-tier density scale, which bases classification primarily on an item's density.

Here’s what’s planned:

Subclass	Freight Density (in lbs per cubic foot)	Freight Class
Sub 1	Less than 1	400
Sub 2	1 but less than 2	300
Sub 3	2 but less than 4	250
Sub 4	4 but less than 6	175
Sub 5	6 but less than 8	125
Sub 6	8 but less than 10	100
Sub 7	10 but less than 12	92.5
Sub 8	12 but less than 15	85
Sub 9	15 but less than 22.5	70
Sub 10	22.5 but less than 30	65
Sub 11	30 but less than 35	60
Sub 12	35 but less than 50	55
Sub 13	50 or greater	50

Over 2,000 commodity listings are intended to be simplified, and new identifiers will help flag freight that have handling, stowability or liability characteristics. These updates aim to improve pricing accuracy and make LTL shipping more consistent.

Starting in July, shippers should provide exact measurements of their freight to ensure proper classification while carriers and 3PLs will benefit from a more streamlined system. The transition is scheduled to begin with the ClassIT online NMFC tool updates on July 15, followed by full implementation on July 19.

To avoid delays or unexpected costs, businesses should start preparing now by reviewing the new classification rules. Working with a carrier that can walk you through these changes can help you avoid delays and unnecessary costs.

Get additional information from the NMFTA

Why freight class and NMFC codes matter

When you ship LTL, your freight shares space with items from other shippers in the same trailer. That’s why NMFC codes — which help carriers quickly understand a commodity — matter. They’re so crucial, in fact, that they’re required on the Bill of Lading (BOL).  

An accurate freight class and NMFC code are necessary for several reasons:  

• It impacts the price. Properly classifying your freight by determining the applicable NMFC Item number will help ensure the quote matches the price on the freight invoice.  

• It determines liability limits. Some carriers offer higher liability limits for higher-class freight. 

• It helps ensure shipments are handled appropriately. How loads are comingled, secured, stacked and protected changes based on the commodity type. 

• It alerts carriers to special requirements. Things like sensitive electronics, medical supplies, pharmaceuticals and hazardous materials may require special license endorsements, placards, equipment types, etc.  

If the shipper doesn’t provide the correct information, a reweigh or remeasurement that changes the class or NMFC code can lead to additional fees and delays.

How to correctly classify your LTL shipment 

To find your shipment’s freight class, start by finding the NMFC commodity or commodities (and sub) — this will determine the freight class.

Talk to your ArcBest Account Representative to learn more about the options and tools we can provide to help you locate the NMFC Item Number and Freight Class for a specific commodity. Don’t have an ArcBest account yet? Click here to get started!

You can also find a specific NMFC code using the NMFTA’s classification tool, ClassIT. And for more information on Freight Classification, check out the NMFTA’s video: Secrets to Efficient Shipping Using the NMFC.