A duplicate lead removal system comprises a matching engine, a vendor duplicates database, and a conflict engine. The matching engine is configured to determine at least one vendor to receive a lead. The vendor duplicates database is configured to store duplicate lead information that is at least partly created by and received from vendors outside of the duplicate lead removal system. The conflict engine is configured to compare information that is at least derived from the lead with information stored in the vendor duplicates database in order to determine if the lead is a duplicate lead for the vendor such that the system can prevent transmission of duplicate leads to the vendor.