NATO Stock Number

A NATO Stock Number, or National Stock Number (NSN) as it is known in the U.S., is a 13-digit numeric code used by the NATO military alliance, identifying all the 'standardized material items of supply' as they have been recognized by all member states of NATO. Pursuant to the NATO Standardization Agreements, the NSN has come to be used in all treaty countries. However, many countries that use the NSN program are not members of NATO (e.g. Japan, Australia and New Zealand). A two-digit Material Management Aggregation Code (MMAC) suffix may also be appended,^[1] to denote asset end use but it is not considered part of the NSN.

In France it is known as a Numéro de Nomenclature OTAN (NNO), or "NATO Identification Number". In Spanish-speaking countries it is known as a Número Nacional de Efecto (NNE), or "National Item Number".

An item having an NSN is said to be "stock-listed".