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Identifiers & Data Linking

When combining data from different sources (e.g., SEC filings with Compustat fundamentals, or Compustat data with analyst forecasts), you need a common identifier to match records. This page provides a quick reference for the most common financial identifiers and how to link datasets.

Common Identifiers

Identifier Assigned by Scope Notes
Ticker Exchanges Exchange-specific Changes over time (mergers, rebranding). Not unique across exchanges.
CIK SEC U.S. SEC filers Central Index Key. Unique to each filer. Used across all EDGAR data.
GVKEY S&P / Compustat Compustat universe Permanent company identifier. Does not change with ticker or name changes.
PERMNO CRSP CRSP universe Permanent security identifier. Unique to each security listing.
CUSIP CUSIP Global Services North America 9-character identifier for securities. Can be recycled after delisting — not permanent.
ISIN National numbering agencies Global 12-character international standard (ISO 6166). First 2 characters = country code, next 9 = local identifier (often CUSIP for US), last = check digit.
SEDOL London Stock Exchange UK / international 7-character identifier widely used in international markets.
LEI GLEIF Global 20-character Legal Entity Identifier for counterparty identification.

Linking Datasets

SEC EDGAR ↔ Compustat (via CIK)

SEC filings use CIK numbers. To link to Compustat:

  1. Use the Compustat company table which contains both gvkey and cik
  2. Or use WRDS Audit Analytics tables that include CIK fields — see the Audit Analytics guide for details

SEC EDGAR ↔ Tickers

The SEC provides a free CIK-to-ticker mapping:

  • company_tickers.json — JSON file mapping CIK numbers to tickers and company names for all SEC filers

CUSIP ↔ ISIN

For U.S. securities, the ISIN is constructed from the CUSIP: - ISIN = "US" + 9-digit CUSIP + check digit - Many databases provide both; if you only have one, the conversion is straightforward

Common Pitfalls

Warning

  • Tickers are not permanent — companies change tickers (e.g., Facebook → Meta: FB → META). Always use permanent identifiers (GVKEY, PERMNO, CIK) for panel data.
  • CUSIPs can be recycled — after a security is delisted, its CUSIP may be reassigned. Use CUSIP + date for unambiguous identification.
  • One company, multiple securities — a single company (one GVKEY/CIK) may have multiple stock classes (multiple PERMNOs/CUSIPs). Be explicit about which security you need.
  • Header vs. body CUSIPs — some datasets use the 6-character issuer code (header CUSIP), others use the full 9-character security-level CUSIP. Make sure you're matching at the right level.

See also: Company Filings (SEC EDGAR) for SEC EDGAR data and CIK lookups | Company Information for annual reports and industry classification | WRDS for Compustat and other database access.