The short answer
- Carriers reclass freight when their dimensioner reading differs from the bill of lading, and the carrier's reading governs when the bill of lading is blank or wrong.
- Itemizing every article with its class on the bill of lading, and keeping templates current after each NMFTA docket, prevents most reclasses.
Why does a carrier reclass a shipment?
An LTL carrier checks freight as it moves through the terminal. A dimensioner measures the handling unit and records its size and weight, and the carrier compares that record with the bill of lading. If the measured size and weight give a different density, and the density gives a different class, the carrier rebills the shipment at the class its own equipment supports.
The carrier's reading governs when the bill of lading is blank or wrong. A bill of lading with no class, no dimensions or a class that does not match the freight gives the carrier nothing to defer to. The same is true when the written dimensions are smaller than the pallet as tendered, because the dimensioner measures the freight as it stands, pallet and projections included.
The corrected bill rarely arrives with the delivery. Rebills come weeks after the freight has delivered, as a separate charge against the original shipment. By then the pallet is unpacked and the evidence is whatever you kept. That timing is why the work in this guide happens before pickup, not after the rebill posts.
Before you book, the freight class calculator estimates the class from your shipment's density, so the class on the bill of lading at least matches your own measurements. A density result is an estimate. The NMFC item for the commodity governs the billed class.
What does NMFC Rule 640 do to mixed pallets?
Rule 640 covers a pallet that holds more than one kind of article. If the bill of lading does not itemize the articles on the pallet, the whole pallet is rated at the highest class among the articles on it. One high-class article, left unlisted, prices the full weight of the pallet at its class.
Say a pallet holds machine parts at class 70 and a boxed display unit at class 250. If the bill of lading lists the pallet as one line with no breakdown, Rule 640 rates the entire pallet at 250. If the bill of lading itemizes the parts and the display unit, each with its own pieces, weight and class, each line rates at its own class and only the display unit's weight pays 250.
Itemizing is cheap insurance. The bill of lading needs a line per article: the description, the piece count, the weight and the class. It takes a few minutes at the dock, and it removes the Rule 640 outcome entirely. The same care applies when freight is added to a pallet at the last minute. A late addition that never made it onto the bill of lading is unitemized freight.
Mixed pallets are common in real shipping, and nothing in Rule 640 bans them. The rule prices silence, not mixing. A complete itemized bill of lading lets a mixed pallet rate article by article.
Why do old templates cause reclasses?
Most shippers store freight classes in templates: a product record, a saved bill of lading, a spreadsheet. Templates go stale because the NMFC changes under them. The National Motor Freight Traffic Association issues dockets that move individual commodity items between classes, and a class that was right last year can be wrong now.
The recent run of changes shows the pace. Docket 2025-1, issued as Disposition Bulletin 1371, replaced the old density scale with a 13-tier scale and took effect on July 19, 2025. Docket 2026-1 took effect on May 23, 2026. Docket 2026-2 takes effect on December 12, 2026. The 13-tier density scale itself did not change in either 2026 docket, but individual commodity items kept moving between classes in both of them.
That split is the trap. A shipper can check the density scale, see that it is unchanged, and conclude that every stored class is still good. The scale is fine and the template is still stale, because the item for one product moved. The fix is a short review after each NMFTA docket: compare the classes in your templates against the current NMFC items for the goods you ship, and update the records that moved. Date the review, so the next one starts from a known point.
What belongs on a complete bill of lading?
A complete bill of lading states what the freight is and how it should rate, in enough detail that the carrier's check confirms it instead of replacing it. For each article, give a description of the goods, the NMFC item number and class where you have them, the number of pieces, the weight, and the dimensions of the handling unit. State the totals, and make sure the lines add up to them.
Dimensions and weight deserve the same care as the class. Measure the handling unit at its greatest length, width and height, pallet and projections included, and weigh the unit as tendered. If you need the density behind the class, the freight density calculator works it out from the dimensions and weight of the handling unit, figured per handling unit the same way the NMFC figures it.
Incomplete bills of lading now carry a direct cost on some carriers. FedEx Freight began enforcing inspection surcharges for incomplete bill of lading information in December 2025. The surcharge pays for the inspection the missing information forces, and it sits on top of any rebill from that inspection. A blank class field is no longer a neutral act. It can trigger a fee, an inspection and a reclass in one shipment.
Print the bill of lading from a current template, check it against the freight on the dock, and keep a copy of the version the driver signed. That signed copy is the document a dispute turns on.
What evidence wins a reclass dispute?
A reclass dispute is a comparison of two records: the carrier's dimensioner reading and your own measurements. The shipper with dated records made before pickup has something to compare. The shipper with a memory of the pallet has an opinion.
Three records carry most disputes. First, photos of the packed pallet with a tape measure held along each side, so the length, width and height can be read from the photo. Second, a copy of the bill of lading as tendered, with the itemized lines and classes on it. Third, scale weight records for the handling unit, from a scale ticket or a dated note of the reading. Together they rebuild the shipment after the freight is gone: size, paperwork and weight.
Add the class calculation to the file. Print the result from the freight class calculator for the shipment's density and keep it with the bill of lading copy, so the class you wrote down has its math attached. If the NMFC item for the commodity assigns the class directly, note the item number in the file.
File the dispute as soon as the rebill arrives, with the evidence attached and the difference stated plainly: the class billed, the class your records support, and the records themselves. Carriers settle disputes on documents. A dispute that arrives with photos, a signed bill of lading and scale records is a short file for the analyst to close in your favor.
Questions
How long after delivery can a reclass arrive?
Rebills arrive weeks after delivery, as a corrected charge against the original shipment. Keep the bill of lading copy, pallet photos and scale records well past the delivery date, because the evidence has to outlast the carrier's billing cycle.
Does a density calculator settle my freight class?
No. A calculator gives a density estimate, and density estimates the class for most goods. The NMFC item for your commodity governs the billed class, and handling, stowability and liability can move a shipment off its density class.
What happens if I leave the class blank on the bill of lading?
The carrier's dimensioner reading governs, and the shipment rates from the carrier's own measurement. On FedEx Freight, incomplete bill of lading information has drawn inspection surcharges since December 2025, so a blank field can cost a fee before any rebill.
Sources
- NMFTA Disposition Bulletins for Dockets 2025-1, 2026-1 and 2026-2
- NMFC Rule 640, mixed articles on one handling unit
- FedEx Freight tariff notes on inspection surcharges
- DIMWeightFinder freight class dataset
Rules last checked: November 12, 2026
This guide is general information, not legal or accounting advice. The NMFC item for your commodity governs the billed class.