A company identifier is a code that refers to one company, or to a security or filer attached to it, and stays the same when the company renames itself. Examples are a legal entity identifier, a securities code, a regulator's filer number and a data vendor's own key.
What each identifies
| Identifier | Identifies | Kept by |
|---|---|---|
| LEI | A legal entity | The Global LEI System, under ISO 17442 |
| ISIN | A security | National numbering agencies, brought together by ANNA, under ISO 6166 |
| FIGI | A listing, or a share class | The Object Management Group standard, served openly by OpenFIGI |
| MIC | A trading venue | ISO 10383, with SWIFT as registration authority |
| CIK | A filer with the US SEC | The SEC |
| Vendor key | A record in one vendor's index | The vendor |
A ticker identifies a listing only together with its MIC, because tickers repeat across venues and can be reused after a delisting. An ISIN identifies a security, not a company, so one company can have several, while an LEI identifies the legal entity that issues them. A company name is not an identifier: names repeat, change and are spelled many ways. GLEIF publishes the LEI records and explains the standard.
Choosing a join key
Join on the identifier that matches what the two datasets describe:
- Prices and holdings: an ISIN, a FIGI or a ticker with its MIC.
- A company's securities grouped together: the LEI.
- SEC filings: the CIK.
- No shared identifier: domain matching first, and names last.
A good key is issued by a named body, is not reused and can be checked: an ISIN and an LEI each carry check digits, which catch many typing errors. Keep the date of each match, because securities are re-issued and companies merge.
In Fokals data
Each company has one stable company ID. A listed company carries its ticker, MIC, ISIN, LEI and share-class FIGI, and its SEC CIK where it has one. A brand or subsidiary carries the identifiers of its listed parent. Identifiers are validated: an ISIN or LEI whose check digit fails is never stored. The data dictionary lists the identifier fields, and the article on the identifiers that make company data joinable describes how they fit together.
Related terms
- ISIN: the 12-character code for a security.
- LEI: the 20-character code for a legal entity.
- FIGI: the open identifier for a listing and its share class.
- Market identifier code (MIC): the four-character code for a trading venue.
- Central Index Key (CIK): the number the SEC assigns to a filer.
Frequently asked questions
What is the best identifier for matching companies across datasets?
There is no single best one, because the right key depends on what you are joining. Use an LEI or the vendor's company key to match legal entities, an ISIN, a FIGI or a ticker with a MIC to match securities and prices, and a CIK to match SEC filings. Where two datasets share none of these, fall back to a normalised domain, and use names last.
Is a ticker symbol a company identifier?
Not on its own. A ticker identifies a listing on one venue, can be reused after a delisting, can change when a company renames itself and differs between venues, so the same ticker can mean different companies in different markets. Pair it with a MIC, or use an ISIN or a FIGI, and keep the date of the match.
What is the difference between an LEI and an ISIN?
An LEI identifies a legal entity, such as the company that issues shares. An ISIN identifies a security that entity issues, such as one class of its shares, so one company can have many ISINs but normally one LEI. Use the LEI to group a company's securities and the ISIN to join to prices and holdings.