ISO 6166

ISO 6166 - an outline of the standard

Securities - International securities identification numbering system (ISIN)

Introduction
The standard provides a uniform structure for a number, known as the lSIN, that uniquely identifies securities. It details organisations, known as National Numbering Agencies (NNA's) that are responsible for issuing the ISIN in each country. In those countries where no NNA is in operation, four NNA's have agreed, on a regional basis, to act as a substitute agency.

ISIN
ISIN consists of a total of 12 characters as follows:

The first two characters are taken up by the alpha-2 country code as issued in accordance with the international standard ISO 3166 of the country where the issuer of securities, other than debt securities, is legally registered or in which it has legal domicile. For debt securities, the relevant country is the one of the ISIN - allocating NNA. In the case of depository receipts, such as ADRs, the country code is that of the organisation who issued the receipt instead of the one who issued the underlying security.

The next nine characters are taken up by the local number of the security concerned. Where the national number consists of fewer than nine characters, zeros are inserted in front of the number so that the full nine spaces are used.

The final character is a check digit computed according to the modulus 10 "Double-Add-Double" formula.

Who issues the ISIN

In the case of securities, other than debt securities, where a NNA recognised by ANNA operates, this organisation issues the ISIN for securities whose issuer is registered or domiciled in the country where the NNA operates. For debt securities the NNA who issues the ISIN is either one of the international securities clearing organisations or the responsible NNA in accordance with ISO 6166.

 

In the case of those countries where no NNA exists, a substitute agency allocates the number.

Click here for the substitute agencies directory.

ISIN structure