What Is a CUSIP Number? How to Look Up Stocks and Bonds
By Markets & Investing DeskUpdated Nov 10, 2026
Definition
A CUSIP number is a nine-character code that identifies one specific U.S. or Canadian security, so every trade, transfer and statement refers to exactly the same instrument.
Key takeaways
- The first six characters identify the issuer, the next two identify the issue, and the ninth is a check digit.
- Many bonds, CDs and commercial paper have no ticker, so the CUSIP is often the only practical way to name them.
- A U.S. ISIN is the CUSIP with a two-letter country prefix and a new check character, as in Apple's US0378331005.
- Mergers, name changes and some restructurings can produce a new CUSIP, leaving old statements with a retired code.
A CUSIP number is a nine-character alphanumeric code that identifies a specific security issued in the United States or Canada, such as a company’s common stock, a municipal bond or a single tranche of corporate notes. Brokers, banks, clearing firms and regulators use it so that every trade, transfer and statement refers to exactly one instrument. CUSIP stands for the Committee on Uniform Securities Identification Procedures, and it is pronounced “Q-sip.”
What Is a CUSIP Number?
A CUSIP works like a serial number for a financial instrument. A ticker such as AAPL is a short trading label assigned by an exchange. A CUSIP is a permanent reference code that back-office systems rely on for clearing, settlement and recordkeeping. Many securities, including most bonds, certificates of deposit, commercial paper and structured notes, have no ticker, so the CUSIP is often the only practical way to name the exact issue.
The system was developed in the 1960s, when growing trade volumes made paper-based identification unworkable. CUSIP Global Services runs it on behalf of the ABA. Standard & Poor’s operated the business for decades, and FactSet bought CUSIP Global Services from S&P in 2022 for about $1.925 billion. The system has covered more than 12.8 million U.S. and Canadian issues (a figure published as of September 2022), and it adds roughly 1,000 to 2,000 new identifiers each day.
CUSIPs are assigned across a wide range of instruments:
| Equity | Debt | Other |
|---|---|---|
| Common and preferred stock | Corporate and municipal bonds | Derivatives and credit derivatives |
| ETFs and mutual funds | Commercial paper | Variable annuities |
| REITs and ADRs | Certificates of deposit | Hedge funds |
| Indexes | Asset-backed securities, CDOs, syndicated loans | Equity-linked notes, capital securities |
How a CUSIP Number Works
Each of the nine positions has a defined role:
- Characters 1 to 6 (CUSIP-6, the base): identify the issuer, such as a company, municipality or government agency.
- Characters 7 and 8 (issue number): identify the specific security from that issuer. By convention, equity issues generally use numeric codes, while debt issues generally use letters or letter-number combinations.
- Character 9 (check digit): calculated from the first eight characters to catch typing and transmission errors.
This is why you will see “CUSIP-6” (the issuer), “CUSIP-8” (the issue, without the check digit) and “CUSIP-9” (the complete identifier used in trading and settlement). Some databases store the 8-character version, so a lookup that fails on nine characters may succeed on eight, or the reverse.
Interpreting a CUSIP Number
The check digit follows a fixed formula:
- Convert each character to a value. Digits keep their value, and letters run from A = 10 through Z = 35.
- Multiply the values in the 2nd, 4th, 6th and 8th positions by 2.
- For each result, add its digits together (for example, 26 becomes 2 + 6 = 8). Then sum all eight results.
- Check digit = (10 − (sum mod 10)) mod 10.
Worked example: 95001DEX4.
| Position | Character | Value | ×2? | Digits summed |
|---|---|---|---|---|
| 1 | 9 | 9 | No | 9 |
| 2 | 5 | 5 | Yes (10) | 1 |
| 3 | 0 | 0 | No | 0 |
| 4 | 0 | 0 | Yes (0) | 0 |
| 5 | 1 | 1 | No | 1 |
| 6 | D | 13 | Yes (26) | 8 |
| 7 | E | 14 | No | 5 |
| 8 | X | 33 | Yes (66) | 12 |
The sum is 36, and (10 − 6) mod 10 = 4, which matches the final character. The code reads as issuer base 95001D, issue code EX (letters, typical of a debt issue) and check digit 4. The check digit only confirms that the code is internally valid. Identifying the issuer and bond still requires a lookup through a broker or an official database.
Why Is a CUSIP Number Important?
Computerized trading and settlement depend on unambiguous identifiers. A single company can have dozens of outstanding bonds with different coupons and maturities, plus several share classes, so two firms describing a trade by name alone can easily book different instruments. When both sides reference the same CUSIP, confirmations, custody records, corporate action notices (dividends, calls, redemptions) and tax reporting all attach to the correct security.
For an ordinary investor, the CUSIP matters most in a few situations:
- buying a specific bond or CD that has no ticker
- transferring holdings between brokers
- researching a municipal bond
- confirming that a statement line refers to the intended share class or note
Example of a CUSIP Number
| Security | CUSIP |
|---|---|
| Apple common stock | 037833100 |
| Alphabet Class A (GOOGL) | 02079K305 |
| Alphabet Class C (GOOG) | 02079K107 |
| Walmart common stock | 931142103 |
| Alaska Air Group common stock | 011659109 |
The two Alphabet lines share the issuer base 02079K, and the issue codes (30 versus 10) separate the share classes. Apple’s check digit of 0 follows from the same formula as the worked example above (the weighted digit sum is 30).
Comparing CUSIP With Other Identifiers
Ticker symbol. Only listed securities have a ticker, and a company can change it. The ticker is what you type to trade; the CUSIP is what the clearing system books.
ISIN. The International Securities Identification Number has 12 characters and is widely used for cross-border trading, though it is not universal. For most U.S. and Canadian securities it is a two-letter country prefix, the CUSIP and a new check character: Apple’s ISIN is US0378331005. Processing an ISIN-based trade also requires the security’s currency.
CINS. The CUSIP International Numbering System extends the nine-character format to securities issued in about 30 markets outside North America. The first character is a letter for the issuer’s country or region; E, for example, indicates Spain. The remaining characters follow the CUSIP layout.
Stock certificate number. The serial number printed on a paper certificate identifies that physical document. The CUSIP printed on the same certificate identifies the class of stock it represents.
Dummy CUSIP and PPN. A dummy CUSIP is a temporary internal placeholder that a firm uses until the official number is assigned. Private placement numbers (PPNs) apply the same identification approach to privately placed debt.
Limitations of a CUSIP Number
- Geographic scope. CUSIPs cover U.S. and Canadian issues. Most foreign-listed securities are identified by CINS or ISIN codes instead.
- Codes can change. Mergers, name changes and some restructurings can lead to a new CUSIP, which leaves old statements carrying a code that no longer trades.
- No economic information. A CUSIP identifies a security. It shows nothing about price, yield, credit quality or risk.
- Proprietary data. The identifiers and their descriptive data are licensed. Free lookups exist, but full databases are a commercial product.
How to Look Up a CUSIP Number
- Broker quote page. Many brokerage quote or security detail pages list the CUSIP next to the ticker, and bond search tools often accept a CUSIP directly.
- Account documents. Trade confirmations and periodic statements typically print the CUSIP for each position.
- Physical certificates. The CUSIP usually appears on the face of stock and bond certificates.
- Municipal bonds. The Municipal Securities Rulemaking Board’s EMMA system lets you search by CUSIP and view official statements and disclosures.
- Your broker or transfer agent. They can confirm which issue a code belongs to, including retired CUSIPs from old holdings.
FAQs
What does "HSBC USA Inc Medium Term Nts Linked R Variabl 04/30/29 B/E" mean?
It is an abbreviated security description of the kind brokers display alongside a CUSIP: medium-term notes issued by HSBC USA Inc., linked to a reference asset or index, with a variable rate, maturing April 30, 2029. "B/E" means book-entry, so the notes are held electronically and no paper certificate is issued. Because issuers often sell many similar notes, use the CUSIP shown with the description to confirm the exact note and its terms.
Is a CUSIP the same on every exchange?
Yes. The CUSIP belongs to the security, not the trading venue, so a stock keeps the same CUSIP wherever it trades in the U.S.
The Bottom Line
Investors need a CUSIP most when buying a bond or CD without a ticker, moving holdings between brokers, or checking that a statement line shows the right share class. The code identifies the security and carries no information about price, yield or risk. Broker quote pages, trade confirmations and the MSRB's EMMA system for municipal bonds are the practical places to find or confirm one.
