Definition — what a CUSIP is
– A CUSIP (pronounced “Q‑sip”) is a nine‑character alphanumeric identifier assigned to individual securities—stocks, bonds and some other instruments—to give each issue a unique, constant label. It was created to make trade processing, clearing and record‑keeping unambiguous.
Key points (high level)
– Unique identifier that applies to a specific security issue (not just the issuer).
– Nine characters long and used primarily by brokers, clearing firms and custodians to settle and track trades.
– Managed by CUSIP Global Services (on behalf of the American Bankers Association); FactSet acquired CGS in 2022.
– Municipal bond CUSIPs and many other issues are publicly accessible via the MSRB’s EMMA system and in routine account statements.
How CUSIP numbers are used (brief)
– Match trade instructions to the exact security being bought or sold.
– Record a security on confirmations, account statements and settlement records.
– Help link domestic securities to international identifiers (see ISIN/CINS below).
How the system scales (quick numeric context)
– CGS issues roughly 1,000–2,000 new CUSIPs per trading day. At that pace, annual issuance is on the order of 365,000–730,000 new identifiers per year.
– CGS oversees millions of U.S. and Canadian CUSIPs (public tallies have shown totals in the millions).
Related identifiers — short definitions
– ISIN (International Securities Identification Number): an international label. When a U.S./Canadian security has an ISIN, the ISIN is formed by adding a two‑character country prefix (for example, “US”) and a final check character to the original nine‑character CUSIP; the resulting ISIN is longer. The extra characters make the identifier usable in cross‑border systems.
– CINS (CUSIP International Numbering System): a nine‑character extension used for securities issued in certain non‑North‑American markets. Its first character can
can be an alphabetic country identifier rather than a numeric issuer code; the rest of the nine characters follow CUSIP-like conventions. CINS codes are used when a security issued outside the U.S./Canada is registered through the CUSIP system so that it can be tracked in North American clearing and settlement systems. CINS is less common than native local identifiers in many markets.
Other related identifiers — short definitions
– SEDOL (Stock Exchange Daily Official List): a seven‑character alphanumeric code issued by the London Stock Exchange’s numbering agency for securities primarily traded in the U.K. and Ireland. It serves a similar role to a CUSIP in British markets.
– FIGI (Financial Instrument Global Identifier): a 12‑character open identifier managed by the Global Legal Entity Identifier Foundation (GLEIF) and used to identify instruments across exchanges and data systems. FIGIs are intended to be non‑proprietary and freely available.
– Ticker symbol (or trading symbol): a short, exchange‑specific abbreviation used to quote prices and identify securities on trading screens. Unlike CUSIPs, tickers are not unique globally—different exchanges can use the same ticker for different securities.
– LEI (Legal Entity Identifier): a 20‑character identifier for legal entities that engage in financial transactions. An LEI identifies the counterparties (issuer, underwriter, holder) rather than the financial instrument itself; it complements security identifiers for regulatory reporting and risk aggregation.
Practical uses of a CUSIP
– Settlement and clearing: matching trade details during post‑trade processing.
– Research and recordkeeping: linking filings, prospectuses, ratings, and trade history to a single security.
– Data integration: joining datasets (prices, corporate actions, holdings) from different vendors.
– Compliance and reporting: regulators and large institutions often require instrument identifiers for filings and internal controls.
How to find a CUSIP — step‑by‑step checklist
1. Check the official offering documents. For bonds, mutual funds, ETFs and new equity issues, the prospectus/official statement usually lists the CUSIP.
2. Look at your trade confirmations or account statements. Brokers and custodians often print the CUSIP for positions you hold.
3. Visit the issuer’s investor relations page. Many corporations and fund families publish the CUSIPs for their securities.
4. Search SEC
4. Search SEC EDGAR — go to the SEC’s EDGAR search (Electronic Data Gathering, Analysis, and Retrieval). Enter the issuer or fund name, open filings likely to contain identifiers (registration statements, prospectuses, 8‑Ks, 424s, N‑1A for funds) and use the browser’s find (Ctrl‑F or Cmd‑F) for “CUSIP” or “CUSIP No.” Filings often list the CUSIP for the specific class or issue.
5. Use commercial market data terminals and databases — Bloomberg, Refinitiv/Refinitiv Workspace, FactSet, Morningstar and others provide CUSIP fields for securities. These are subscription services; search by ticker, issuer or ISIN and read the security header/identifier fields.
6. Check CUSIP Global Services (CGS) — CUSIP assignment and the authoritative master list are maintained by CUSIP Global Services. CGS offers lookup and licensing options; access is typically fee‑based for direct queries or bulk files.
7. Ask the intermediary or issuer — contact your broker, custodian, transfer agent or the issuer’s investor relations group. They can confirm the exact CUSIP for the share class, bond issue, or fund share you hold or intend to trade.
8. Cross‑check other identifiers — if you have an ISIN (International Securities Identification Number) you can often map it to a CUSIP (for U.S. securities the ISIN embeds the 9‑character CUSIP). Also compare with ticker symbols, SEDOL (UK), or local identifiers to avoid mismatches between classes or maturities.
Worked example — computing the CUSIP check digit
CUSIP is 9 characters: first 8 identify issuer+issue, the 9th is a numeric check digit calculated from the first 8. Here’s how the check digit is calculated, applied to the common Apple example whose full CUSIP is 037833100:
1. Take the first 8 characters: 0 3 7 8 3 3 1 0. Numeric digits map to themselves; letters map A=10 … Z=35
2. Apply the alternating weights 1 and 2 to the numeric values, starting with weight 1 on the first (leftmost) character.
3. For any product >= 10, reduce it by summing its digits (equivalently, subtract 9). This is the “digit-sum” step used in the CUSIP modulus algorithm.
4. Sum all adjusted products.
5. Compute the check digit as: check digit = (10 − (sum mod 10)) mod 10. This yields a single digit 0–9.
Worked Apple example (first 8 characters already given: 0 3 7 8 3 3 1 0)
– Step 2 (weights): weights are 1, 2, 1, 2, 1, 2, 1, 2.
– Multiply each value by its weight:
– 0 × 1 = 0
– 3 × 2 = 6
– 7 × 1 = 7
– 8 × 2 = 16 → digit-sum 1+6 = 7 (or 16 − 9 = 7)
– 3 × 1 = 3
– 3 × 2 = 6
– 1 × 1 = 1
– 0 × 2 = 0
– Step 4 (adjusted products): 0, 6, 7, 7, 3, 6, 1, 0
– Step 5 (sum): 0 + 6 + 7 + 7 + 3 + 6 + 1 + 0 = 30
– Check digit = (10 − (30 mod 10)) mod 10 = (10 − 0) mod 10 = 0
Therefore the full CUSIP is 037833100 (the final digit 0 is the check digit).
Notes, pitfalls and quick checklist
– Character mapping: digits 0–9 map to 0–9; letters A–Z map to 10–35. Three special characters sometimes used map as: ‘*’ → 36, ‘@’ → 37, ‘#’ → 38. Confirm any non-alphanumeric characters before computing.
– Weighting: always alternate 1,2 starting from the leftmost of the eight identifier characters.
– Digit-sum vs. subtract-9: when a product is ≥10 you may either sum its