CUSIP Lookup: Find a Security's CUSIP From SEC Filings

A ticker symbol is not the only identifier a security carries. Most US and Canadian stocks and bonds also have a CUSIP, a nine-character code that shows up constantly in SEC filings, from 13F holdings reports to Schedule 13D cover pages, even though most investors never look one up directly.

What a CUSIP is

CUSIP stands for Committee on Uniform Securities Identification Procedures, the industry committee that created the numbering system in the late 1960s. Today CUSIP numbers are issued and maintained by CUSIP Global Services, operated by FactSet on behalf of the American Bankers Association. A CUSIP identifies one specific security, not a company in general, which is the main reason it differs from a ticker symbol.

How a CUSIP is structured

A CUSIP is nine characters long, split into three parts:

The check digit is calculated with a fixed formula applied to the first eight characters, which lets systems catch simple transcription errors before a trade settles on the wrong security. Because the issue-level characters vary, one company can have a different CUSIP for its common stock, its preferred stock, and each of its outstanding bond issues, all sharing the same six-character issuer prefix.

CUSIP vs ticker

A ticker is convenient for looking up a stock quote, but it is exchange-specific and tied to the common equity that trades day to day. A CUSIP is the identifier filers use when the filing is about the security itself, including share classes and debt that never gets a ticker at all. A bond, a warrant, or a non-traded preferred share generally has a CUSIP even when it has no ticker symbol anywhere, which is part of why filings that cover fixed income or multiple share classes rely on CUSIPs rather than tickers to stay precise.

Why CUSIPs show up in SEC filings

Several SEC forms require filers to report the CUSIP of the security they are disclosing, because a company name or ticker alone is not precise enough when a filing covers one class of stock among several, or a bond rather than equity:

• Schedule 13D and 13G cover pages require the CUSIP number of the class of securities being reported, since a beneficial ownership filing is about one specific class.
• Form 13F information tables list a CUSIP for every reported holding, because an institutional manager's portfolio spans many issuers and often more than one share class per issuer.
• Form 13F cover pages and amendments reference CUSIPs for prior holdings being amended.

This means EDGAR itself is a free, practical way to find the CUSIP for a widely held security, simply by finding any 13F holdings table or Schedule 13D or 13G that reports a position in it, even though the complete CUSIP master file is a commercial product licensed from CUSIP Global Services and not something the SEC publishes in full.

Looking up a CUSIP from filings data

curl "https://secfeedapi.com/v1/mapping/cusip?cusip=037833100" \
  -H "Authorization: Bearer YOUR_API_KEY"

from secfeed import Client

sf = Client("YOUR_API_KEY")
match = sf.map_cusip("037833100")
print(match)

The lookup works by matching the CUSIP against issuer names reported for it in 13F holdings tables, then matching that issuer name to a ticker and CIK where possible. Because the underlying data comes from 13F filings, coverage reflects securities that institutional managers have actually reported holding since Form 13F data begins in 2013, not a complete registry of every CUSIP ever issued. Full parameters at /docs/#v1-mapping-cusip.

Going the other direction: ticker or CIK to CUSIP

If you already know the company and want its CUSIP, searching /v1/form-13f/holdings or a Schedule 13D or 13G for that issuer's name will surface the CUSIP reported for it, since both datasets carry the CUSIP alongside the issuer name on every row.

Frequently asked questions

Does the SEC assign CUSIP numbers?

No. CUSIP numbers are issued and maintained by CUSIP Global Services, a commercial service operated by FactSet on behalf of the American Bankers Association. The SEC requires filers to report CUSIPs in certain forms, but it does not assign them.

Can one company have more than one CUSIP?

Yes. A CUSIP identifies a specific security, such as one class of common stock, one class of preferred stock, or one bond issue. A company with multiple share classes or outstanding bonds has a separate CUSIP for each one, all sharing the same six-character issuer prefix.

Is there a free, complete CUSIP database?

Not an official one. The full CUSIP master file is a licensed commercial product. Individual CUSIPs for widely held securities are freely visible in SEC filings that are required to report them, such as Form 13F holdings tables and Schedule 13D and 13G cover pages, which is why EDGAR data can answer most practical CUSIP lookups without a license.

What is the difference between a CUSIP and an ISIN?

A CUSIP identifies US and Canadian securities. An ISIN is a broader international identifier used globally, and for most US securities it is built by adding a country prefix and a new check digit to the existing CUSIP.

Why would a CUSIP lookup from SEC filings not find a result?

If a security has never appeared in a Form 13F holdings table or a Schedule 13D or 13G, there is no filing-based record linking that CUSIP to an issuer name, even though the CUSIP itself may still exist in the licensed CUSIP Global Services database.