ISIN.net can assist in converting your ISIN code to a SEDOL code.
SEDOL stands for Stock Exchange Daily Official List, a list of security identifiers used in the United Kingdom and Ireland for clearing purposes. SEDOLs serve as the National Securities Identifying Number for all securities issued in the United Kingdom and are therefore part of the security’s 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, much like an ISIN identifies a security.