ISIN

International Securities Identifying Number (ISIN)

An ISIN uniquely identifies a fungible security, its structure is defined in ISO 6166. Securities with which ISINs can be used include debt securities, shares, options, derivatives and futures.

ISINs consist of two alphabetic characters, which are the ISO 3166-1 code for the issuing country, nine numeric digits (the National Securities Identifying Number, or NSIN, which identifies the security), and one numeric check digit. The NSIN is issued by a national numbering agency (NNA) for that country. Regional substitute NNAs have been allocated the task of functioning as NNAs in those countries where NNAs have not yet been established.

ISINs are slowly being introduced worldwide. At present, many countries have adopted ISINs as a secondary measure of identifying securities, but as yet only some of those countries have moved to using ISINs as their primary means of identifying securities.