SEDOL

SEDOL (Stock Exchange Daily Official List) is a seven-character alphanumeric code used to uniquely identify securities, principally those traded on the London Stock Exchange and other UK and Irish markets. Issued by the London Stock Exchange, SEDOLs serve as a stable, widely used local identifier for reference data, trade confirmation, settlement, and risk management.

Code structure and check digit: The first six characters encode the instrument; the seventh character is a single-digit check digit. In the calculation, letters are assigned values A=10 through Z=35, digits carry their face value, and each position is multiplied by a weight of 1, 3, 1, 7, 3, 9 respectively. The weighted sum is taken modulo 10, and the check digit is (10 minus that remainder) modulo 10. This ensures the code can be validated automatically.

Scope: SEDOLs cover a wide range of UK and Irish securities, including common stocks, bonds, and ADRs with UK exposure. They are used by market participants and data vendors, and many instruments issued outside the UK may also be assigned a SEDOL. SEDOLs are often used in conjunction with ISINs, and the London Stock Exchange maintains a SEDOL Master File that maps SEDOLs to other identifiers.

Usage: In practice, SEDOLs appear in trading, settlement, and reference data feeds as persistent identifiers that support cross-market data matching and record keeping. They facilitate interoperability among systems that rely on local identifiers, and corporate actions or issuer changes are reflected in updated SEDOL records. The code itself does not imply any financial characteristics.

Related identifiers include ISIN and CUSIP; the SEDOL Master File, maintained by the London Stock Exchange Group, maps SEDOLs to other identifiers.