A CUSIP (Committee on Uniform Securities Identification Procedures) is a unique nine-character numeric or alphanumeric code that identifies a North American financial security for the purposes of facilitating clearing and settlement of trades. It is used to identify most financial instruments, including stocks of all registered U.S. and Canadian companies, commercial paper, and U.S. government and municipal bonds. The CUSIP system is owned by the American Bankers Association (ABA) and is operated by FactSet Research Systems Inc. The operating body, CUSIP Global Services (CGS), also serves as the national numbering agency (NNA) for North America, and the CUSIP serves as the National Securities Identification Number (NSIN) for products issued from both the United States and Canada.

A CUSIP number consists of nine characters (including letters and numbers) that uniquely identify a company or issuer and the type of financial instrument. The first six characters are known as the base (or CUSIP-6), and uniquely identify the issuer. The 7th and 8th digit identify the exact issue, and the 9th digit is a checksum. The last three characters of the issuer code can be letters, in order to provide more room for expansion.

CUSIP Global Services also has a series of other important identifiers along with CUSIP. Two of these are ISIN (International Securities Identification Number) and CINS (CUSIP International Numbering System), which are used to identify foreign securities. ISIN is primarily used in Europe, where it is a requirement for securities trading and reporting, while CINS is used in more than 30 non-North American markets.

CUSIP numbers are used primarily by brokerage and clearing firms to ensure that transactions are properly settled and recorded. As an ordinary investor, CUSIP numbers are not of much use. If you need to look up a CUSIP number, you can contact CUSIP Global Services or visit its website.