Stackable vs Non-Stackable Freight
Stackable vs non-stackable freight affects trailer space, freight class, pricing, and damage risk. Learn how to decide and how to declare it on your BOL.
Stackable freight is packaged so another compatible handling unit can be placed on it safely and securely under the applicable carrier rules. Non-stackable freight cannot safely accept freight above it because of its shape, strength, stability, contents, or packaging.
This is a physical and operational distinction, not a preference box to check for a better rate. A flat top alone does not make freight stackable, and a warning label does not correct an inadequate package. Evaluate the completed handling unit and report its status accurately when requesting a quote.
Stackable and non-stackable at a glance
| Question | Stackable freight | Non-stackable freight |
|---|---|---|
| Top and base | Flat, stable, and suitable for vertical loading | Irregular, unstable, too narrow, or otherwise unsuitable |
| Package strength | Designed to accept the expected top load | Could be crushed or damaged by freight above it |
| Load shape | Square, level, and contained within the base | Peaked, domed, protruding, top-heavy, or irregular |
| Carrier handling | May provide more loading options | Requires protected vertical space or special handling |
| Quote entry | Declare stackable only when the package supports it | Declare non-stackable and follow carrier marking rules |
| Pricing | Based on the carrier’s normal rating rules | May trigger a service-specific surcharge or different space treatment |
Carrier definitions and charges vary. FedEx, for example, defines a non-stackable freight handling unit as one that cannot be stacked vertically in a safe and secure manner. Its examples include units without a flat and stable top or base, units that may be damaged by freight above them, and narrow units that cannot safely support another handling unit. That definition and its surcharge apply to the services named in FedEx’s guide; it is not a universal tariff for every LTL carrier.
What makes freight genuinely stackable?
A stackable pallet needs more than a level-looking top. The complete package must remain stable and protect its contents while carrying the load permitted by its design.
Review:
- Pallet strength, condition, and support under the freight
- Carton, crate, or container compression strength
- Internal product support and cushioning
- Load pattern and weight distribution
- Top surface area and stability
- Center of gravity
- Overhang, projections, and irregular edges
- Film, straps, corner protection, blocking, and bracing
- Any commodity-specific NMFC packaging requirements
- The carrier’s current service and acceptance rules
Uniform cartons stacked in aligned columns on a sound pallet can be a strong starting point. FedEx notes that column stacking increases top-to-bottom compression strength in almost all cases. Even then, damaged cartons, unsupported deck gaps, weak contents, excessive height, moisture, or an inadequate pallet can make the completed load unsuitable for top loading.
Do not add a top cap and call the pallet stackable. A cap can protect or distribute force, but it cannot create strength that the cartons and product do not have.
What makes freight non-stackable?
Freight may be non-stackable because another handling unit cannot sit on it securely or because the product would be damaged by the load above. Common reasons include:
- A peaked, domed, curved, sloped, or uneven top
- A narrow footprint that cannot support another unit safely
- Fragile contents or packaging that cannot accept compression
- Protrusions, exposed components, or an irregular shape
- A top-heavy or unstable handling unit
- A package that is damaged, wet, crushed, or poorly supported
- A product or package design that expressly prohibits top loading
- Service-specific or commodity-specific restrictions
Some freight is non-stackable by its nature. Other freight becomes non-stackable because of the way it was packaged. In the second case, redesigning the crate, carton stack, support, or pallet may create a safe stackable handling unit. That decision should come from a valid packaging design, not from tightening straps around a weak load.
Why the distinction affects price
Trailer and container capacity is three-dimensional. A handling unit that cannot accept freight above it can limit how the carrier uses the vertical space around that position. Some services address that constraint with a non-stackable surcharge or other rating treatment.
The exact consequence depends on the carrier, service, lane, dimensions, and tariff. Do not assume that every carrier charges the same fee or uses dimensional weight in the same way. Obtain a shipment-specific quote using the correct stackability status.
Stackability also should not be confused with freight class. NMFTA identifies density, handling, stowability, and liability as the four principal classification factors. A non-stackable package may present stowability or handling concerns, but there is no universal rule that checking “non-stackable” changes every commodity to a particular class.
Packaging can still affect classification inputs. A larger package can reduce density, while projections or an irregular shape can affect stowability and handling. Use the applicable NMFC provision and current carrier rules rather than guessing from the pallet’s appearance.
How to evaluate a pallet before quoting
1. Inspect the base
Use a pallet or other handling base that supports the finished weight and remains accessible to the required material-handling equipment. Reject broken boards, split components, protruding fasteners, or inadequate support.
2. Inspect the package
Confirm cartons, crates, closures, cushioning, blocking, and bracing are suitable for the commodity. Keep freight within the pallet footprint. Overhang reduces support and exposes edges to impact.
3. Examine the top surface
A stackable unit should have a flat, stable loading surface, but geometry is only the first test. Verify that the load path beneath that surface can carry the intended force without crushing the packaging or product.
4. Check stability
The freight should not lean, rock, or move independently of the pallet. Unitize it using the materials required by the packaging design. Stretch film, straps, edge boards, and top protectors each serve different roles and do not substitute for internal product protection.
5. Confirm the applicable rules
Check the NMFC packaging requirements for the commodity and the current rules for the carrier and service. If the package has not been evaluated for top loading, ask the carrier, packaging supplier, or a qualified packaging professional before declaring it stackable.
How to prepare stackable freight
- Build a square, level, fully supported load with no overhang.
- Use packaging strong enough for the contents and expected compression.
- Keep the center of gravity controlled and the weight distributed appropriately.
- Protect corners and edges where film or bands apply force.
- Secure the load to the pallet without crushing the package.
- Leave fork and pallet-jack openings unobstructed.
- Measure and weigh the handling unit after packaging is complete.
Never state a universal maximum height or weight for stackable freight. Equipment, service, carrier, pallet, commodity, and package limits can differ materially.
How to prepare non-stackable freight
Non-stackable does not mean lightly packaged. The handling unit still needs a sound base, suitable outer packaging, internal protection, and secure unitization.
Follow the selected carrier’s current instructions for declaring and marking non-stackable freight. That may involve a shipping-system field, handling instruction, label, or other service-specific process. Do not rely on an improvised cone or handwritten note unless the carrier accepts it.
Place required markings where they remain visible, and keep them consistent with the quote and shipping documents. A mismatch between the declared status and the physical package can lead to inspection, delay, rerating, or other outcomes under the carrier’s rules.
Mistakes to avoid
- Declaring a pallet stackable because its top merely looks flat
- Using a top cap to hide an unsupported or weak load
- Calling damaged cartons stackable to avoid a possible charge
- Assuming a warning label guarantees how every carrier will handle the unit
- Leaving stackability out of the quote and adding it only at pickup
- Using another carrier’s height, weight, surcharge, or marking rule
- Measuring the product before its final pallet and packaging are installed
- Treating stackability as a universal freight-class switch
Enter the finished shipment accurately
After packaging, record the greatest finished length, width, and height, including the pallet and every projection. Record the gross weight including packaging. Current NMFTA guidance permits carriers to verify shipment weight and dimensions, so the quoted handling unit should match what is tendered.
Prepare the pallet count, commodity description, NMFC item and class when applicable, stackability of each handling unit, origin and destination ZIP codes, and required pickup or delivery services.
Shipocity is backed by a team with more than 40 years of combined logistics experience. Through established industry relationships, the platform helps businesses compare competitive freight rates for their specific shipment.
