CUSIP Validator

CUSIP: the North American identifier for securities

The CUSIP (Committee on Uniform Security Identification Procedures) is a 9-character alphanumeric code that uniquely identifies a security issued in the United States or Canada: common stock, preferred stock, corporate bonds, municipal bonds, US Treasuries, mutual funds, options and structured notes. The standard was created in 1964 by the American Bankers Association to enable electronic clearing and settlement after the Wall Street paperwork crisis, and is administered today by CUSIP Global Services (CGS), a business of S&P Global operating under licence from the ABA.

Although CUSIPs are formally a North American identifier, they have become the de facto backbone of the global ISIN scheme: a US or Canadian ISIN is simply US or CA followed by the 9-character CUSIP plus an extra Luhn check digit. For Brazilian investors holding US ADRs (Petrobras PBR, Vale VALE, Itau ITUB, Ambev ABEV), the CUSIP is what appears on the broker custody statement and on SEC filings.

Anatomy of the 9 characters

• Positions 1-6 (issuer code): identify the company or government entity. Examples: 037833 Apple Inc., 594918 Microsoft, 912828 US Treasury notes, 00206R AT&T.
• Positions 7-8 (issue code): identify the specific instrument issued by that entity. Common conventions: 10 for common stock, 20-29 for preferred classes, alphanumeric codes for debt tranches.
• Position 9 (check digit): a single decimal digit computed by a modified Luhn over a digit-mapped representation of the first eight characters.

Check-digit algorithm step by step

Each of the first 8 characters is converted to a numeric value: digits 0-9 keep their value; letters A-Z become 10-35; the special symbols allowed are * = 36, @ = 37 and # = 38. Characters in odd positions (1, 3, 5, 7) are doubled; if doubling yields a two-digit number the digits are added together. All values are summed; the check digit is (10 - sum mod 10) mod 10.

CUSIP 037833100 (Apple Inc.)
0 3 7 8 3 3 1 0 -> digits 0,3,7,8,3,3,1,0
double odd positions; sum digits; DV = (10 - sum mod 10) mod 10 = 0

CUSIP vs ISIN, CINS, SEDOL, FIGI and Bloomberg ticker

North American markets historically used CUSIP exclusively; international compatibility came later through ISIN.

• ISIN (ISO 6166): 12-character global identifier. For US/CA securities the ISIN is built by prefixing US or CA to the CUSIP and appending one more Luhn check digit (e.g., Apple ISIN US0378331005).
• CINS (CUSIP International Numbering System): same 9-character layout as a CUSIP but the first character is always a letter that encodes the country of the issuer (e.g., P for South America, B for the UK). Used for non-US/CA securities cleared in the US.
• SEDOL: 7-character UK identifier, not interchangeable with CUSIP.
• FIGI: Bloomberg-led 12-character open standard, free via the OpenFIGI API, often used to cross-walk between CUSIP, ISIN and tickers.
• Bloomberg ticker (e.g., AAPL US Equity): a Bloomberg-specific identifier, separate from CUSIP and FIGI.

Use cases and licensing

• SEC filings: Form 13F holdings reports, mutual fund disclosures and prospectuses identify securities by CUSIP.
• FINRA TRACE: corporate bond trade reporting in the US is keyed on CUSIP.
• DTCC: the Depository Trust & Clearing Corporation settles US equities and bonds using CUSIP as the primary key.
• Municipal bonds: the MSRB EMMA system publishes disclosures by CUSIP.
• Licensing cost: bulk access to the CUSIP database is paid (roughly US$2,000-5,000 per year for basic feeds, much more for redistribution rights). OpenFIGI is a free alternative for mapping when the use case allows.

Common pitfalls

• Confusing CUSIP with SEDOL: SEDOL has 7 characters, CUSIP has 9 — they are not interchangeable even though both identify securities.
• Mixing CUSIP and CINS: both look like 9-character codes but CINS always starts with a letter and follows different jurisdictional rules.
• Reuse after delisting: CGS can retire and later reuse a CUSIP for a different instrument; always combine with an as-of date.
• Licensing traps: redistributing CUSIPs without a CGS licence has triggered legal action — store the mapping under your contract terms.

FAQ

Is CUSIP used only in the United States?

It is the primary identifier in the US and Canada. For non-US/CA securities cleared through US systems the related CINS format is used; outside North America the global ISIN is the norm.

Can I derive an ISIN from a CUSIP?

Yes. For US securities the ISIN is US + 9-character CUSIP + Luhn check digit; for Canadian securities it is CA + CUSIP + Luhn. Apple 037833100 becomes ISIN US0378331005.

Is the CUSIP database free?

No, bulk CUSIP data requires a paid licence from CGS. For mapping needs, OpenFIGI by Bloomberg offers a free public API that returns the FIGI and often the related CUSIP for a given query.

Does this validator query a live securities database?

No. It only runs the modified Luhn check digit in your browser. A pass result confirms the 9 characters are arithmetically well-formed; it does not guarantee that the security exists or is currently active.

How is a CUSIP different from a SEDOL?

CUSIP has 9 alphanumeric characters and covers the US/Canada; SEDOL has 7 alphanumeric characters and is issued by the London Stock Exchange for UK and international securities. They use different check-digit algorithms and are not interchangeable.