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. SEDOLs serve as the NSIN for all securities issued in the United Kingdom and are therefore part of the security's ISIN as well. For security (collateral), the legal right given to a creditor by a borrower, see security interest A security is a fungible, negotiable interest representing financial value. ... The Source by Greyworld, in the new LSE building Paternoster Square. ... A National Securities Identifying Number or NSIN is a generic nine digit number which identifies a fungible security. ... An International Securities Identifying Number (ISIN) uniquely identifies a security. ...

Although SEDOL was to have been superseded by ISIN, problems with the ISIN system have since forced a reversal of this decision. In particular, a single ISIN is used to identify the shares of a company no matter what exchange it is being traded on, making it impossible to specify a trade on a particular exchange or currency. For instance, Chrysler trades on twenty-two different exchanges worldwide, and is priced in five different currencies. An expanded ISIN standard is currently being formulated to address this problem. For other uses, including the Chrysler Brand, see Chrysler (disambiguation). ...

Description

SEDOLs consist of two parts, a six-place alphanumeric code and a trailing check digit. Sedols issued prior to January 26, 2004 were comprised only of numbers. For those older SEDOLs, those from Asia & Africa typically begin with 6, those from the UK & Ireland (until Ireland joined the EU) typically begin with 0 or 3 those from Europe typically began with 4, 5 or 7 and those from the America's began with 2. Ranges beginning with 1 and 9 were reserved for end user allocation. A check digit is a form of redundancy check used for error detection, the decimal equivalent of a binary checksum. ...

Because older sedols may begin with a leading zero, when importing a raw file containing sedols into Excel, care must be taken to import that sedol column as text, so that the leading zeros are not dropped.

The check digit for SEDOL uses a weighted sum of the first six digits. Letters are converted to numbers by adding their ordinal position in the alphabet to 9, such that A = 10 and Z = 35. The resulting string of numbers is then multiplied by the weighting factor as follows:

 First 1 Second 3 Third 1 Fourth 7 Fifth 3 Sixth 9 

The character values are multiplied by the weights. The check digit is modulo 10 (10 - this sum modulo 10). The word modulo (Latin, with respect to a modulus of ___) is the Latin ablative of modulus which itself means a small measure. ... The word modulo (Latin, with respect to a modulus of ___) is the Latin ablative of modulus which itself means a small measure. ...

For British and Irish securities, SEDOLs are converted to ISINs by padding the front with two zeros, then adding the country code on the front and the ISIN check digit at the end.

Example

BAE Systems: 0263494 BAE Systems plc is the worlds third largest defence contractor,[3] the largest in Europe and a commercial aerospace manufacturer. ...

The checksum can be calculated by multiplying the digits by their weightings:

(0×1, 2×3, 6×1, 3×7, 4×3, 9×9) = (0, 6, 6, 21, 12, 81)

Then summing up the results:

0 + 6 + 6 + 21 + 12 + 81 = 126

The check digit is then calculated by:

modulo 10 (10 - (126 modulo 10)) = modulo 10 (10 - 6) = 4 The word modulo (Latin, with respect to a modulus of ___) is the Latin ablative of modulus which itself means a small measure. ... The word modulo (Latin, with respect to a modulus of ___) is the Latin ablative of modulus which itself means a small measure. ... The word modulo (Latin, with respect to a modulus of ___) is the Latin ablative of modulus which itself means a small measure. ...

Perl Code:

 use POSIX; print getSCD($ARGV[0])."n"; sub getSCD{ my $sedol = shift; my @t = split //,$sedol; my $sum = 0; my @wt = (1,3,1,7,3,9); for(my $i=0; $i<6; $i++){ my $tt = $t[$i]; my $v = 0 + (ord($tt) - ord('0')); $v = 10 + (ord($tt) - ord('A')) if $tt =~ /[A-Z]/; $sum += $v*$wt[$i]; } my $d = floor($sum/10); $d = $sum - 10*$d; $d = 10 -$d; $d = 0 if $d == 10; return $d; } 

VBA Code:

 Public Function getSedolCheckDigit(str) ' calculates the final digit of a six digit sedol code using the algo described on wikipedia If Len(str) <> 6 Then getSedolCheckDigit = "Six chars only please" Exit Function End If Dim mult(6) mult(1) = 1: mult(2) = 3: mult(3) = 1: mult(4) = 7: mult(5) = 3: mult(6) = 9 ' didn't use Array() to avoid Option Base problems Dim i, total, s total = 0 For i = 1 To 6 s = Mid(str, i, 1) total = total + IIf(IsNumeric(s), Val(s), Asc(s) - 64) * mult(i) Next getSedolCheckDigit = (10 - (total Mod 10)) Mod 10 End Function 

External Links

• SEDOL validation code in C
• London Stock Exchange