ISIN Validator
Validate ISINs and the CUSIP or SEDOL inside them, with the country.
About this tool
Paste one or more ISINs. Each is checked for structure and its check digit, the country prefix is named (including XS for international bonds), and for US/CA and GB/IE ISINs the embedded CUSIP or SEDOL is extracted and its own check digit verified.
How ISINs are built
An ISIN (International Securities Identification Number, ISO 6166) uniquely identifies a share, bond, ETF, fund or other security in trading and settlement worldwide. It's 12 characters: a 2-letter prefix (usually the issuer's country, or XS for international securities cleared through Euroclear or Clearstream), a 9-character national identifier (the NSIN), and a check digit. To compute the check digit, letters become numbers (A=10 … Z=35) and the Luhn algorithm runs over the resulting digit string. Inside, US and Canadian ISINs carry a CUSIP: Apple's ISIN US0378331005 contains CUSIP 037833100, which has its own modulus 10 check. UK and Irish ISINs usually contain a SEDOL with weights 1-3-1-7-3-9: BAE Systems' GB0002634946 contains SEDOL 0263494. The validator checks all three, which is useful for cleaning portfolio exports, data feeds and spreadsheets. Honest limits: a valid ISIN may belong to a delisted or matured security, and the tool doesn't fetch names or prices. Check with your broker, the exchange or a national numbering agency. Not financial advice. The check digit calculator and the stock profit calculator are related.
Frequently asked questions
What is an ISIN?
A 12-character code that identifies a security worldwide: country prefix, 9-character national ID and a check digit.
How is the ISIN check digit calculated?
Convert letters to numbers (A=10…Z=35), then apply the Luhn algorithm to the digits.
What is the difference between ISIN and CUSIP?
A CUSIP is the 9-character US/Canadian ID. The ISIN wraps it with a country code and check digit.
Is my data sent anywhere?
No. Everything is checked in your browser, and nothing is stored, looked up online or sent.