International Securities Identification Number

An International Securities Identification Number (ISIN) uniquely identifies a security. Its structure is defined in ISO 6166. Securities for which ISINs are issued include bonds, commercial paper, and warrants. The ISIN code is a 12-character alpha-numerical code that does not contain information characterizing financial instruments but serves for uniform identification of a security through normalization of the assigned National Number, where one exists, at trading and settlement.

Securities to which ISINs can be issued include debt securities, shares, options, derivatives and futures. ISIN cannot specify a particular trading location in this case, and another identifier, typically MIC (Market Identifier Code) or the three-letter exchange code, will have to be specified in addition to the ISIN. The Currency of the trade will also be required to uniquely identify the instrument using this method.

ISINs were first used in 1981, but didn't reach wide acceptance until 1989, when the G30 countries recommended adoption. The ISIN was endorsed a year later by ISO with the ISO 6166 standard.

Where an existing national numbering scheme already existed, this was used as the bases for the ISIN code. For example the Wertpapierkennnummer (WKN). The old code was embedded in the ISIN with the addition of the country code and usually padded to leading zeros to fit, Initially information was distributed via CD-ROMs and this was later replaced by distribution over the internet.

In 2004 the European Union mandated the use instrument identifiers in some of its regulatory reporting, which included ISIN as one of the valid identifiers.

ISO 6166 (or ISO6166:2013 as of the 2013 revision) defines the structure of an International Securities Identifying Number (ISIN). An ISIN uniquely identifies a fungible security. Securities with which ISINs can be used are , debts, ETFs, options, derivatives, and futures.

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