ISIN
The twelve-character International Securities Identification Number that uniquely identifies a security worldwide.
How it is identified
ISIN = 2-letter country code + 9-character national identifier + 1 check digit (12 characters total)
Unit
qualitative
In depth
The ISIN is the identifier that depositories, custodians and clearing systems actually use, so it is the one that governs settlement — a trade settles against an ISIN, not a ticker. Indian ISINs begin with 'IN', and every distinct instrument gets its own: equity shares, each series of debentures, each mutual fund plan. It survives name changes and differs between exchanges' tickers, which makes it the correct key for any database that must stay accurate for years. Because a single company can have many ISINs, an ISIN identifies a security rather than an issuer.
Worked example
One company may carry an ISIN for its equity shares, another for a partly paid rights share, and a third for a listed non-convertible debenture. All three trade separately at separate prices, and only the ISIN keeps them apart when instructions reach the depository.
Illustrative figures, chosen so the arithmetic is easy to follow. Not a live price and not a valuation of any company.
Educational reference only
This entry explains what “ISIN” means. It is not investment advice and not a recommendation to buy or sell any security. Any numbers above are illustrative, not live prices, and nothing here predicts price direction or rates a stock. Consider your own circumstances and consult a SEBI-registered investment adviser before acting.