# CUSIP vs ISIN vs FIGI: which identifier to build on

Tickers are free and ambiguous. CUSIP, ISIN and SEDOL are unambiguous and licensed. FIGI, LEI and CIK are unambiguous and free — start there.

*https://stockmarketstack.com/guides/cusip-isin-figi-identifiers · background to Stock Market Data APIs*

**Answer:** A ticker identifies a listing at a moment, not a security: it gets reused after a delisting, differs by venue and by share class, and changes on corporate actions. CUSIP, ISIN and SEDOL are stable but licensed, and the licence covers storing and redistributing the numbers themselves. FIGI and LEI are open, free and resolvable through public APIs, and with the SEC's CIK they cover almost everything a first project needs.

Two data sources disagree about what a security is, and you are three tables into a schema that
assumed a ticker was a key. This is where everybody finds out that the identifier question has an
industry behind it.

## Why the ticker fails

A ticker identifies a listing at a moment in time. Four things break it, all four verifiable in
the SEC's own data.

**It gets reused.** Bed Bath & Beyond Inc. filed with the SEC under CIK 886158 until September
2023, when the registrant was renamed 20230930-DK-Butterfly-1, Inc. and stopped trading. The
ticker BBBY now appears in EDGAR's company data against a different registrant entirely — CIK
1130713, which filed as Overstock.com until 2023, then as Beyond, Inc., then as Bed Bath &
Beyond, Inc., and which EDGAR listed under another name again in August 2026. One ticker, two
unrelated issuers, three years apart.

**It differs per share class.** Alphabet has one CIK, 1652044, and two listed classes: GOOGL for
the Class A shares and GOOG for the Class C — different votes, different prices, different
identifiers all the way down. Anything treating "Alphabet" as one row has already lost.

**It differs per venue.** The same instrument trades in several places under a different local
symbol in most of them — the gap venue-level identifiers exist to fill.

**It changes on corporate actions.** EDGAR records Meta Platforms' former name, Facebook Inc.,
through 27 October 2021, and lists META as the ticker today. The CIK never moved: anything keyed
on FB broke, anything keyed on 1326801 did not.

## How it works

Five registries matter, and they are not the same kind of thing.

**CUSIP** — nine characters, United States and Canada. The American Bankers Association owns the
system; [CUSIP Global Services](https://www.cusip.com/identifiers.html) administers it and is,
per its own page, "managed on behalf of the American Bankers Association by FactSet Research
Systems Inc." FactSet announced the purchase of CGS from S&P Global in December 2021 and
[closed it on 1 March 2022](https://www.sec.gov/Archives/edgar/data/1013237/000095015722000210/ex99-1.htm)
for approximately 1.925 billion dollars. CGS is also the national numbering
agency for the United States.

**ISIN** — twelve characters, international, ISO 6166. Issued by national numbering agencies —
over 120 of them, per CGS — coordinated by ANNA, which is the registration authority for the
standard. Two rules from ANNA's own
[ISIN Uniform Guidelines](https://anna-web.org/wp-content/uploads/2025/11/ISIN-Guidelines-Dec-2025_Amendment_clean.pdf)
(Version 25, December 2025) set the limits: an ISIN identifies "a financial instrument rather than
the market a financial instrument trades on", except for options, futures and commodities, and
"ISINs should never be re-used". So it survives a delisting and tells you nothing about where the
thing traded. A US ISIN is also a CUSIP in a wrapper, sitting in positions 3 to 11: Apple's US
ISIN is US0378331005, and the nine characters in the middle are the part with a licence on them.

**SEDOL** — seven characters, assigned by the London Stock Exchange, now part of
[LSEG](https://www.lseg.com/en/data-analytics/market-data/data-analytics-pricing/data-symbology/sedol)
(the market-data business formerly called Refinitiv — not Reuters, which is the news agency).
LSEG says the SEDOL Masterfile covers over 100 million instruments. SEDOL is listing-level where
ISIN is instrument-level — which is why European reference data carries both.

**FIGI** — twelve characters, and the interesting one. The
[specification](https://www.omg.org/spec/FIGI/) is published by the Object Management Group,
with Bloomberg as registration authority, and the identifiers are open data: OpenFIGI's own
[API page](https://www.openfigi.com/api) says the API is "free to use without daily, weekly or
monthly limitations". It is also the
only scheme here explicit about levels. Apple has an exchange-level FIGI per venue, a composite
FIGI per country — BBG000B9XRY4 for the US — and one share class FIGI, BBG001S5N8V8, tying every
listing of that share class together worldwide. A mapping request for the ticker AAPL returned 74
rows in September 2026; the same request for the US ISIN returned 272, which measures how much a
single ISIN is hiding.

**LEI** — twenty characters, ISO 17442, run by GLEIF under a G20 and Financial Stability Board
mandate, identifying the legal entity rather than the instrument. Post-2008 reporting rules are
why it exists and why it has scale: GLEIF's
[Q2 2026 business report](https://www.gleif.org/lei-data/global-lei-index/download-global-lei-system-business-reports/download-global-lei-system-business-report-q2-2026/q2-2026-quarterly_business_report.pdf)
puts the active population past 3.1 million, with about 92,000 issued in that quarter alone.

Two more fill the gaps. **PermID** is LSEG's open identifier for organisations, instruments and
quotes, free to query after registration — read its terms first, because it publishes no bulk
redistribution licence this page could find. **CIK** is the SEC's registrant number: free, and the key
to everything in EDGAR.

## What it costs

The ticker costs nothing and is worth it. Allocating an ISIN is mostly free too: ANNA's guidelines
say the majority of NNAs do not charge for allocation and levy nothing for maintenance, on a
cost-recovery basis where they charge at all. The money is not in issuing the numbers. It is in
using them.

SEDOL is the one scheme that publishes its rate card, so it is the one that shows the shape. From
LSEG's 2026 pricing guidelines, a Limited User Licence runs £1,065 per year for up to 1,000 SEDOL
codes within one legal entity, £3,335 for 1,001 to 5,000 and £10,930 for 5,001 to 10,000; higher
education institutions pay £1,065 for any number; distribution licences start at £985 per year.
Read the trigger rather than the prices: a "Licensable Event" is receiving, accessing, extracting,
processing, adapting, reproducing or storing SEDOL codes, and it counts codes reachable through a
third-party application as well as codes in your own database.

CGS publishes no equivalent document: its terms describe the numbers and standard descriptions as
the ABA's intellectual property, licensed for defined internal use rather than redistribution, and
the price is whatever the agreement you sign says. FIGI, LEI and CIK cost nothing at any volume.
The [OpenFIGI mapping API](https://www.openfigi.com/api/documentation) allows 25 requests a minute
and 10 jobs per request unauthenticated, 25 requests per 6 seconds and 100 jobs with a free key;
GLEIF's [LEI Data Terms of Use](https://www.gleif.org/en/meta/lei-data-terms-of-use/) place the LEI
data under a CC0 licence.

## What the regulator and the court actually said

Stated narrowly, because the narrow version is strong enough.

In **Case COMP/39.592 — Standard & Poor's**, the European Commission
[adopted a commitments decision](https://ec.europa.eu/competition/antitrust/cases/dec_docs/39592/39592_2152_5.pdf)
on 15 November 2011 (C(2011) 8209 final). In its statement of objections the Commission
took the preliminary view that S&P's licence fees for US ISINs were unfair: that charging
*indirect* users — banks, brokers and fund managers who took US ISINs from information service
providers rather than from S&P and held them in their own databases — did not follow the ISO cost
recovery principle, and that S&P owned no copyright in US ISINs, as a database or as individual
numbers. S&P committed to abolish all charges to indirect users within the EEA and to
distribute US ISIN records separately from other data by daily FTP at an initial price of 15,000
US dollars a year. Three limits matter: an Article 9 decision does not conclude whether there was
an infringement, and the decision says so; the commitments applied to the EEA only; and by their
own terms they ran five years from the implementation date, which has long passed.

In the United States, **Dinosaur Financial Group LLC v. S&P Global, Inc., American Bankers
Association and FactSet Research Systems Inc.**, No. 22 Civ. 1860 (KPF) in the Southern District
of New York, was filed on 4 March 2022. On 14 July 2023 the court granted the motion to dismiss
in part, dismissing the Sherman Act Section 1, copyright and breach of contract claims and
allowing the remainder to proceed. On 28 August 2026 the court
[resolved](https://storage.courtlistener.com/recap/gov.uscourts.nysd.576062/gov.uscourts.nysd.576062.411.0.pdf)
the parties' expert-exclusion motions and granted class certification in a sealed opinion — and
on 10 September 2026 it
[vacated that opinion](https://storage.courtlistener.com/recap/gov.uscourts.nysd.576062/gov.uscourts.nysd.576062.417.0.pdf)
and struck it from the docket, directing briefing by 13 October 2026 on whether distributors
belong in the certified class. Nothing has been decided on the merits, and class certification is
unresolved as of the date on this page. Anyone telling you a court has ruled on CUSIP licensing is
describing something that has not happened.

## What to key your database on

Not a ticker, and not a licensed identifier either. Use an internal surrogate id as the primary
key, and hold every external identifier in a child table of `(scheme, value, source, as_of_date)`
rows you append to rather than overwrite. The as-of
date is the part people skip and the part that saves the migration: when two vendors disagree, the
question is usually which of them is a year behind a corporate action, and a row without a date
cannot answer it.

Then pick the FIGI level deliberately: share class for "the asset", composite for "the asset in
this country", exchange-level for "the thing that printed this trade".

## What you can do about it

**Building something public, open source, or that you might have to hand to somebody else:** FIGI
plus LEI plus CIK. All three are free, all three are redistributable, and none involves a licence
conversation — which is what makes them the only set that survives a repository being cloned by a
stranger, as anything in [open source](https://stockmarketstack.com/collections/open-source) will be.

**Working with US filings:** CIK is your key, and it is free. The
[EDGAR APIs](https://www.sec.gov/search-filings/edgar-application-programming-interfaces) serve
company submissions and XBRL company facts as JSON keyed on it, including every former name — which
is how the ticker-reuse examples above were checked. If an assistant is doing the reading,
[SEC EDGAR MCP](https://stockmarketstack.com/tools/sec-edgar-mcp) resolves a ticker to a CIK and works from filing data rather
than scraped pages.

**Mapping between two vendors:** post your identifiers to the OpenFIGI mapping endpoint,
`https://api.openfigi.com/v3/mapping`, which accepts tickers, ISINs, SEDOLs, CUSIPs and about
thirty other types and returns FIGIs. Know the limit: it resolves *into* FIGI and does not return
a CUSIP or an ISIN, so it is a bridge between systems, not a way around a licence. Dead tickers
return nothing — BBBY resolved to "No identifier found" — which is correct, and a good test of
your error path. If the pain is provider churn rather than symbology, [OpenBB](https://stockmarketstack.com/tools/openbb) puts
one interface over many providers, and [Databento](https://stockmarketstack.com/tools/databento) is worth reading for its
symbology model alone.

**A counterparty, custodian or regulator demands ISIN or CUSIP:** then you licence. CUSIP and US
ISIN come from CUSIP Global Services; SEDOL from LSEG. Expect a contract sized by how many codes
you store or can reach rather than how many you query, with redistribution priced separately and
reporting obligations attached. Ask for the trigger definition in writing before you ask for a
price — LSEG's published one counts codes merely *accessible* through a third-party application.

**Buying data rather than identifiers:** most providers in
[market data APIs](https://stockmarketstack.com/categories/market-data-apis) return an ISIN or a CUSIP on a plan that includes
them, usually the cheapest lawful route to those numbers for a small shop —
[EODHD](https://stockmarketstack.com/tools/eodhd) and its peers cover the exchanges where ticker collisions are a daily
problem. Check what the vendor's terms let you *store* and *pass on*: the vendor's licence and the
identifier's licence are two different documents.

The free identifiers are one part of a larger free layer — [what regulators and central banks
publish](https://stockmarketstack.com/guides/free-financial-data-sources) covers the rest — and the licensing that makes the
others cost money is mapped in [who owns the market data
industry](https://stockmarketstack.com/guides/who-owns-market-data).

## Tools this bears on

- [SEC EDGAR MCP](https://stockmarketstack.com/tools/sec-edgar-mcp.md) — SEC filings and XBRL financials as MCP tools, under AGPL or a paid commercial licence.
- [Databento](https://stockmarketstack.com/tools/databento.md) — Full order book and tick history from exchange feeds, billed by the gigabyte.
- [OpenBB](https://stockmarketstack.com/tools/openbb.md) — One Python API, REST app and MCP server over thirty other people's data feeds.
- [EODHD](https://stockmarketstack.com/tools/eodhd.md) — End-of-day and fundamentals for 60+ exchanges worldwide, at a hobbyist price.

## FAQ

### Is CUSIP free to use?

No. CUSIP Global Services describes CUSIP numbers and their standard descriptions as the intellectual property of the American Bankers Association, and licenses them for defined internal use rather than for redistribution. CGS publishes no rate card, so the price of a licence is whatever your negotiated agreement says. Printing a CUSIP in an article is not the issue; shipping a database of them is.

### What is a FIGI?

A 12-character alphanumeric identifier defined by an Object Management Group standard, with Bloomberg as the registration authority. It is open data, free to use and free to redistribute, and it exists at three levels — one FIGI per venue listing, a composite FIGI per country, and a share class FIGI that links the same share class worldwide.

### Is a US ISIN the same thing as a CUSIP?

Almost. CUSIP Global Services is the national numbering agency for the United States, and a CGS-issued ISIN carries the CUSIP in positions 3 to 11 — US, then the nine CUSIP characters, then a check digit. That is why the licensing question attached to CUSIPs follows the US ISIN abroad, and why the European Commission opened proceedings about US ISIN fees in January 2009 that ended in binding commitments in 2011.

### How do I map a ticker between two data providers?

Map both sides to something that is not a ticker. The OpenFIGI API accepts tickers, ISINs, SEDOLs, CUSIPs and around thirty other identifier types and returns FIGIs, free and without a daily cap. It resolves inbound identifiers into FIGI; it does not hand back a CUSIP or an ISIN, so it is a bridge, not a licence workaround.

### Can I look up an LEI for free?

Yes, including in bulk. GLEIF publishes the whole Global LEI Index — over 3.1 million active LEIs at the end of the second quarter of 2026 — as daily Golden Copy files under GLEIF's LEI Data Terms of Use, which place the data under a CC0 licence. Obtaining an LEI for your own entity is a paid service from an accredited issuer; reading everyone else's is not.

## Sources

1. [CUSIP Identifiers](https://www.cusip.com/identifiers.html) — CUSIP Global Services, 2026-09-04
2. [ISIN Uniform Guidelines relating to ISO 6166 (8th edition), Version 25](https://anna-web.org/wp-content/uploads/2025/11/ISIN-Guidelines-Dec-2025_Amendment_clean.pdf) — Association of National Numbering Agencies, 2025-12-01
3. [SEDOL Masterfile Pricing and Policy Guidelines 2026](https://www.lseg.com/content/dam/lseg/en_us/documents/sedol/sedol-masterfile-pricing-and-policy-guidelines-2026.pdf) — LSEG, 2025-09-24
4. [Financial Instrument Global Identifier (FIGI), Version 1.3 beta](https://www.omg.org/spec/FIGI/) — Object Management Group, 2026-08-01
5. [Global LEI System Business Report Q2 2026](https://www.gleif.org/lei-data/global-lei-index/download-global-lei-system-business-reports/download-global-lei-system-business-report-q2-2026/q2-2026-quarterly_business_report.pdf) — GLEIF, 2026-07-23
6. [EDGAR Application Programming Interfaces](https://www.sec.gov/search-filings/edgar-application-programming-interfaces) — U.S. Securities and Exchange Commission, 2025-04-08
7. [Order (Dkt. 411), Dinosaur Financial Group LLC v. S&P Global, Inc., No. 22 Civ. 1860 (KPF)](https://storage.courtlistener.com/recap/gov.uscourts.nysd.576062/gov.uscourts.nysd.576062.411.0.pdf) — U.S. District Court, S.D.N.Y. (via CourtListener RECAP), 2026-08-28
8. [Order (Dkt. 417), Dinosaur Financial Group LLC v. S&P Global, Inc., No. 22 Civ. 1860 (KPF)](https://storage.courtlistener.com/recap/gov.uscourts.nysd.576062/gov.uscourts.nysd.576062.417.0.pdf) — U.S. District Court, S.D.N.Y. (via CourtListener RECAP), 2026-09-10
9. [Commission Decision of 15.11.2011, Case COMP/39.592 - Standard & Poor's (C(2011) 8209 final)](https://ec.europa.eu/competition/antitrust/cases/dec_docs/39592/39592_2152_5.pdf) — European Commission, 2011-11-15. An adopted decision is a record of what was decided that day. A later case can supersede it; a fresher copy of itself cannot.
10. [FactSet Completes Acquisition of CUSIP Global Services (Exhibit 99.1 to Form 8-K)](https://www.sec.gov/Archives/edgar/data/1013237/000095015722000210/ex99-1.htm) — FactSet Research Systems Inc. (via SEC EDGAR), 2022-03-01. A completed acquisition. CGS still names FactSet as its operator, which is the fact this supports.
11. [OpenFIGI API Overview](https://www.openfigi.com/api) — OpenFIGI, read 2026-09-14
12. [OpenFIGI API Documentation](https://www.openfigi.com/api/documentation) — OpenFIGI, read 2026-09-14
13. [LEI Data Terms of Use](https://www.gleif.org/en/meta/lei-data-terms-of-use/) — GLEIF, read 2026-09-14

*Last updated 2026-09-14. A reference page, corrected in place — not a dated post.*