We have found IDLookup an invaluable tool for avoiding the creation of duplicates during bulk imports, and have included it as a step in all of our bulk processing procedures. Each of these features a stage where a standardised .csv file is extracted for running against IDLookup (enabling the use of a standard mapping file), the Output file from which is then used to supply ConsID numbers for the import file – this also enables us to easily identify those donors that are not already on the database and import them as new constituents. We are also using IDLookup for deduping the main database itself, as it is far more powerful than the duplicate-checking functionality built into Raiser’s Edge.