The Full Form of SEDOL is‍ Stock Exchange Daily Official List.

SEDOL stands for Stock Exchange Daily Official List, a list of security identifiers used in the United Kingdom and Ireland for clearing purposes. The numbers are assigned by the London Stock Exchange, on request by the security issuer. 

The Stock Exchange Daily Official List (SEDOL), is a list of security identifiers used in the United Kingdom and Ireland for clearing purposes. The seven-digit numbers are assigned by the London Stock Exchange, on request by the security issuer. SEDOLs serve as the National Securities Identifying Number or NSIN for all securities issued in the United Kingdom and are therefore part of the security’s International Securities Identifying Number or ISIN as well. The SEDOL Masterfile (SMF) provides reference data on millions of global multi-asset securities each uniquely identified at the market level using a universal SEDOL code.

SEDOLs are seven characters in length, consisting of two parts: a six-place alphanumeric code and a trailing check digit. SEDOLs issued prior to January 26, 2004 were composed only of numbers. For older SEDOLs, those from Asia and Africa typically began with 6. Those from the UK and Ireland (until Ireland joined the EU) typically began with 0 or 3. Those from the rest of Europe typically began with 4, 5, or 7. Those from the Americas began with 2.