Types of LPNs and How LPN Relates to SKU, SSCC, and Serial Numbers

LPNs can represent different handling units (pallet, case, tote) and coexist with SKUs, SSCCs, GTINs, and serial numbers to provide layered traceability and inventory control.

Types of LPNs and How LPN Relates to SKU, SSCC, and Serial Numbers

In warehouse and inventory management, LPN (License Plate Number) is a flexible identifier that can be applied to a variety of handling units. Understanding the different types of LPNs and how they interact with product identifiers such as SKUs, GTINs, SSCCs, and serial numbers is essential to designing inventory systems that balance efficiency and traceability.

Types of LPNs by handling unit

LPNs are commonly used to represent specific physical units. The primary categories include:

• Pallet LPN: Assigned to full pallets. Useful for inbound/outbound movements, cross-docking, and bulk storage.

• Case LPN: Assigned to full cases or cartons where cases are handled as discrete units for picking or shipping.

• Tote/Carton LPN: Used in piece-picking or sortation environments where individual totes or cartons carry mixed SKUs.

• Container/Trailer LPN: Larger units such as sea containers or trailers may receive container-level LPNs for transport tracking.

• Bin or Location LPN: Some operations assign LPN-like identifiers to fixed storage locations for simplified scanning and reconciliation, though these are technically location IDs.

• Lot or Batch LPN: For lot-controlled products, LPNs can be tied to lot numbers and expiration dates to aid recalls and shelf-life management.

LPN versus SKU, GTIN, SSCC, and serial numbers

Understanding the distinction between these identifiers helps you apply LPNs effectively:

• SKU (Stock Keeping Unit): A SKU defines a distinct product variant (size, color, configuration) for inventory accounting and ordering. SKUs represent what the items are, while LPNs represent the physical container that holds items. A single LPN can contain multiple SKUs.

• GTIN (Global Trade Item Number): GTINs identify trade items globally (e.g., UPC, EAN). GTINs are product identifiers for barcode labels on saleable units; LPNs are container identifiers that may reference GTINs for contained items.

• SSCC (Serial Shipping Container Code): SSCC is a GS1 standard for uniquely identifying logistic units. In many cross-border, carrier, and trading partner contexts, an SSCC serves as the LPN, ensuring interoperability between parties.

• Serial numbers: Serial numbers identify individual serialized items for warranties and end-to-end traceability. Serial-level tracking is more granular than LPNs and often requires different capture workflows (scan each serialized item vs. scan the containing LPN).

When to use which identifier

Choosing the right mix depends on operational and compliance needs:

• High-volume, low-variance distribution: Use pallet and case LPNs plus SKU references to maximize throughput. Serial-level tracking is rarely needed.

• Regulated industries (pharmaceuticals, food): Combine LPNs with lot/expiration and possibly SSCC standards. Traceability often requires linking LPNs to lot and batch records.

• High-value or serialized products (electronics, aerospace): Maintain serial-level tracking in addition to LPNs so both handling units and individual items are traceable.

• Multi-party logistics: Adopt SSCC as the LPN when partners expect GS1-compliant codes for cross-docking, consolidation, and shipment handoffs.

Mapping strategies and data models

Effective systems model the relationships between identifiers. Typical data relationships include:

• One LPN > contains > multiple SKUs/GTINs (with quantity per SKU)

• One SSCC (used as LPN) > references > lot numbers and expiration dates

• One serialized item > assigned to > an LPN when packed

WMS and inventory systems should support multi-level packing hierarchies, allowing operations to break or combine LPNs (split a pallet LPN into multiple case LPNs or merge several tote LPNs into one shipment LPN) while preserving lineage to SKUs, lots, and serial numbers.

Practical examples

A consumer electronics 3PL receives a crate that contains multiple serialized TVs. Each TV has a serial number; the crate also receives an LPN used for receiving and putaway. During order picking, the WMS instructs workers to pick by serial numbers and associate those serials with a new tote LPN for shipment, thereby preserving both serialized traceability and container-level handling efficiency.

Conclusion

LPNs are a complementary layer of identification in the inventory ecosystem. They enable efficient handling of physical units while interoperating with product identifiers like SKUs and GTINs and traceability constructs like SSCCs and serial numbers. Designing the right combination depends on throughput needs, traceability requirements, partner standards, and the capability of your WMS and ERP systems.