The stock exchange daily official list (SEDOL) is a seven-character identification code for securities that are listed on the London Exchange. SEDOL is used by companies and issuers to identify assets.
Until January 2004, all SEDOL codes contained only numeric values; then, alphanumeric codes were introduced.
The first six characters are an alphanumeric sequence, and the seventh character is a trailing check digit. Letters are only used from the B to Z range, which is related to the fact that vowel letters are not used. The numeric values are from 0 to 9.
The method of checking this code is that the weighted sum of all characters must be a multiple of 10. For this process, the letters are assigned a value corresponding to their position in the alphabet and added to 9. For example, the letter B in the English alphabet is 2 letters by count. Then the assigned value is 11; this is 9 + 2.
The utility of SEDOL code is not only in its uniqueness but also in that it covers different types of assets, making it easier and more secure to track the necessary financial instrument.
An example of an earlier assignment of SEDOL code is the HSBC stock code of SEDOL: 0540528. This code was assigned in 1991 and contains only numerical values. A more recent example is the Antofagasta bond, 2.375% 14oct2030, USD SEDOL: BMDGCK2. An example of a similar code is CUSIP, used to identify US and Canadian securities.