Understanding freight class and NMFC codes is essential for anyone shipping via Less Than Truckload (LTL) freight. These classifications determine how shipments are priced, handled, and stored throughout the supply chain. In fact, industry research suggests that up to 25% of shipping invoices contain classification errors, inflating freight charges and leading to billing disputes.
In this article, we break down how freight class and NMFC codes work together, why accuracy matters more than ever in 2025, and how you can avoid costly missteps in the LTL shipping process.
What Are NMFC Codes and Why Do They Matter?
The National Motor Freight Classification (NMFC) system uses unique numerical identifiers to classify commodities based on their characteristics. These NMFC codes are critical for Less Than Truckload (LTL) shipping because they directly influence your freight class and, by extension, your shipping costs.
Each freight classification corresponds to a specific class ranging from Class 50 (least expensive) to Class 500 (most expensive). Lower classes generally indicate durable, dense goods, while higher classes typically involve items that are bulky, fragile, or more difficult to handle.
Using the correct freight class ensures accurate pricing and reduces the risk of disputes. Misclassifying a shipment can lead to unexpected charges, delivery delays, or billing errors. Always use a reliable freight classification reference to categorize cargo correctly.
Breaking Down Freight Class Descriptions
Shipping class is determined by a system that takes four primary factors into account:
- Density – The space an item occupies relative to its weight
- Storability – How easily it fits and stacks during transport
- Handling – The effort and equipment needed to move it
- Liability – Risk of theft, damage, or legal complexity
There are 18 standard shipping classes. Lower numbers are reserved for compact, durable items. Higher numbers go to oversized or delicate goods. Understanding these distinctions helps avoid costly classification mistakes and streamlines your shipping process.
While those factors define freight class at a technical level, let’s explore what they actually mean in the real world—starting with how tricky items require special care during shipping.
Handling: What Makes Certain Items Tricky?
Not all shipments are created equal. Certain items require specialized handling—regardless of what the freight class technically indicates. Here are examples of tricky shipments that can lead to damage or disputes if not prepared properly:
- Glass or ceramics – Require extra padding, double-boxing, and fragile labels.
- Perishables – Need insulated packaging and faster delivery options.
- Hazardous materials – Must comply with government handling and labeling standards.
- High-value electronics – Often require tamper-proof seals and GPS tracking.
Startups and growing businesses should prepare for these complexities early in their fulfillment planning.
The Role of NMFC in Accurate Freight Classification
Using NMFC classification codes helps standardize pricing, simplify quoting, and ensure goods are handled consistently throughout the LTL network. It also supports transparency between shippers and carriers.
By using the correct freight class, you can:
- Classify your shipment accurately
- Avoid misquotes and unexpected fees
- Speed up order processing and reduce delays
Digital tools like shipment class calculators and NMFC lookup tools make it easier than ever to classify shipments precisely.
Of course, even the most accurate classification won’t help if your shipment is packaged or labeled incorrectly—leading to carrier refusals or damage claims.
Best Practices for Packaging and Labeling Freight
Packaging and labeling go hand-in-hand with freight classification. Even if your shipment is properly coded, poor labeling or fragile packaging can still delay delivery or increase costs.
Use the following checklist:
- Use strong, stackable boxes suited to your product’s weight.
- Include clear labels with correct addresses, contact info, and barcodes.
Use visual handling instructions like “Fragile” or “This Side Up.” - Eliminate excess void space inside the box to prevent shifting.
- Make labels visible and durable enough to survive the shipping process.
These steps improve shipment reliability and protect your freight investment.
How to Determine Freight Class for Your Shipment
To accurately determine the freight class for your LTL shipment, follow these steps:
Measure Dimensions and Weight
Calculate the density of your shipment by dividing the total weight by the total cubic feet. Using a freight density calculator ensures precision in this calculation, helping you avoid errors in classification.
Identify the Commodity
Determine the specific characteristics of the item you’re shipping. Consider factors like fragility, stowability, and handling requirements, as these influence your cargo type and shipping classification code.
Use the NMFC Lookup Tool
Access the NMFC database and use a lookup tool to find the appropriate freight class for your commodity. This step ensures your freight is categorized correctly according to standard freight classification guidelines.
Cross-Reference the Freight Class Chart
Match the shipping classification code you’ve identified to the corresponding cargo type using a cargo type chart. This ensures you select the correct class for your shipment, minimizing the risk of disputes or additional fees.
Accurate classification isn’t a one-time task—it requires ongoing awareness.
Staying Informed on NMFC Code Changes
Staying informed means routinely reviewing updates published through the NMFC database and monitoring industry announcements. Businesses that track NMFC database changes proactively are better prepared for audits, pricing shifts, and regulatory updates tied to freight classification.
Common Missteps When Using NMFC Codes and How to Avoid Them
Misusing NMFC codes or misinterpreting shipment classifications can lead to costly errors. Here are some common mistakes and how to avoid them:
- Using Outdated Codes: Always check the latest shipping classification code updates to ensure your classification is correct.
- Incorrect Density Calculation: Use a density calculator to determine accurate pounds per cubic foot.
- Assuming Similar Items Share the Same Type: Even slight variations in a commodity can change its cargo type.
Avoid these mistakes by double-checking your NMFC codes and using tools like the shipping classification code lookup tool and cargo type calculator.
Even when you use the right tools, confirmation adds an extra layer of protection.
Confirming NMFC Codes with Your Carrier or Freight Forwarder
Before shipping, confirm your NMFC code with your carrier or freight forwarder. They often cross-check classifications against the NMFC database used for rating and billing.
This step helps align expectations, reduce invoice corrections, and ensure both parties reference the same NMFC database information.
How Frequently Are NMFC Codes Updated?
NMFC codes are reviewed and updated regularly by the National Motor Freight Traffic Association. Updates may occur several times a year to reflect new products, materials, or shipping practices. Because changes are published through the NMFC database, shippers should avoid relying on old classifications and instead verify codes using the current NMFC database before each shipment.
Why Density Matters in Freight Classification
Freight density—calculated as total weight divided by cubic feet—is a foundational component of determining freight class.
Here’s why it matters:
- A box of pillows may weigh the same as a box of tools, but takes up far more space—leading to a higher class and cost.
- Denser freight typically earns a lower classification and cheaper rates.
Formula: Density = Weight ÷ Cubic Feet
The 2025 NMFC changes will give more weight to density when assigning freight classes. By optimizing how items are packed and minimizing excess volume, shippers can reduce costs and avoid reclassification charges.
When density rules or commodity definitions shift, your existing classification may no longer apply.
What to Do If Your NMFC Code Changes
If your NMFC code changes, update your internal shipping records immediately and reclassify affected SKUs. Review packaging, density, and handling requirements, then confirm the revised classification using the NMFC database. Acting quickly helps prevent reclassification fees and billing disputes tied to outdated NMFC database entries.
Having the right resources makes ongoing compliance far easier to manage.
Resources for Staying Current on NMFC Code Changes
Reliable resources include the official NMFC database, carrier bulletins, freight classification software, and guidance from logistics partners. Many businesses also rely on automated tools that pull directly from the NMFC database to flag changes and prevent outdated classifications from entering the shipping workflow.
Simplify Freight Classification with Supply Chain Solutions
We understand that freight classification can feel overwhelming, especially with evolving standards and complex codes. That’s why Supply Chain Solutions is here to make the process easier. Our expert team helps businesses like yours navigate classification challenges, prevent costly errors, and optimize shipping strategies for long-term success.
Contact us today to simplify your freight classification and improve logistics efficiency with confidence.
