NSNs

NSNs, short for National Stock Numbers, are 13-digit codes used to identify, classify, and manage military materiel across NATO and allied nations. They enable standardized naming and cross-border interoperability in procurement, stocking, and logistics, allowing items to be referenced unambiguously in different countries’ supply systems. The NSN format consists of a four-digit Federal Supply Class (FSC) code and a nine-digit National Item Identification Number (NIIN).

The NIIN uniquely identifies the item within its FSC and typically includes a two-digit country code plus a seven-digit item number assigned by a national codification bureau. NSN data are maintained in the NATO Master Catalogue of References (NMCR), which links each NSN to standardized item data such as the official name, synonyms, unit of issue, and packaging details.

Administration and use: NSNs are issued under the NATO Codification System by national codification bureaus. In the United States, the Defense Logistics Agency maintains the U.S. catalog and assigns NSNs. Once an item receives an NSN, the number remains with that item even if suppliers or specific part numbers change, ensuring continuity in ordering and inventory control. NSNs are used throughout the supply chain—from procurement and storage to maintenance and distribution—to support interoperability among partner forces and international suppliers. They cover a broad range of items, including spare parts, raw materials, finished goods, and indirect items.