International Securities Identification Number (ISIN)
An International Securities Identification Number (ISIN) is a 12-digit alphanumeric code that uniquely identifies a specific security. The organization that allocates ISINs in any particular country is the country's respective National Numbering Agency (NNA).An ISIN should not be confused with a stock ticker symbol, which is a shorter code that only identifies the exchange on which the security trades. For example, Apple Inc.'s stock trades on multiple exchanges under the ticker symbols AAPL and APPL. Each of these has its own unique ISIN.The first six characters of an ISIN are known as the "prefix", and they identify both the NNA and the type of security. The next nine characters are known as the "body", and they uniquely identify the exact security within each class identified by the prefix. For example, all U.S.-traded common stocks have an ISIN prefix of US0-. So, Apple Inc.'s common stock traded on Nasdaq would have an ISIN of US0378331005, while its common stock traded on NYSE would have an ISIN of US0378331055. Lastly, the final character is called the check digit and it's used to verify that the previous 11characters are correctly entered. The check digit is computed using a special formula and then verified against a lookup table maintained by the issuing NNA.
