ISIN — International Securities Identification Number
An ISIN is a 12-character code defined by ISO 6166 that identifies a specific security — a share class, a bond, a warrant — uniquely worldwide. It identifies the instrument, not the company and not the venue: the same share listed on three exchanges keeps one ISIN.
- Standard
- ISO 6166
- Length
- 12 characters
- Check digit
- Modulus-10 (Luhn-style) check digit
- Answers
- What — the security
- Steward
- National numbering agencies, coordinated by ANNA
- Authoritative registry
- Issuer filings / national numbering agency
- Licensing
- Open — free to use and redistribute
- Coverage in our dataset
- 108 of 121 covered companies
Anatomy of the code
| Part | In the example | Meaning |
|---|---|---|
| Positions 1–2 | US | ISO 3166 country prefix of the issuing numbering agency (not necessarily where the company operates) |
| Positions 3–11 | 037833100 | National security identifier — for US and Canadian ISINs this is exactly the CUSIP |
| Position 12 | 5 | Check digit, modulus 10 |
Validate one now
The validator on the Identifiers page recognises ISIN automatically and checks its check digit in your browser — nothing is sent to a server.
Open the validator with ISIN example Parsing code (Python / TypeScript)
Questions
What is an ISIN?
An ISIN is a 12-character code defined by ISO 6166 that identifies a specific security — a share class, a bond, a warrant — uniquely worldwide. It identifies the instrument, not the company and not the venue: the same share listed on three exchanges keeps one ISIN.
How is an ISIN check digit calculated?
Letters are converted to numbers (A=10 … Z=35), the resulting digit string is processed with a Luhn-style modulus-10 algorithm, and the final digit makes the total divisible by 10. A single mistyped character almost always breaks it, which is why validating an ISIN before storing it catches most data-entry errors.
Does an ISIN contain the CUSIP?
For US and Canadian securities, yes: positions 3 to 11 of the ISIN are the CUSIP. That is why a US ISIN can be converted to a CUSIP without a licence, while CUSIP data itself remains licensed.
Is an ISIN the same as a ticker?
No. A ticker is venue-local shorthand and can be reused across markets — the same three letters can mean different companies in New York and London. An ISIN is globally unique for the security.
The other identifiers
Every financial fact needs four resolutions: who (LEI), what (ISIN/FIGI/CUSIP/SEDOL), where (MIC) and in what unit (ISO 4217). The Standards page shows how they fit together; Identifiers resolves them against our data. seed-0.6 · 2026-08-29.