A core charge is a deposit until you return your old part. Mechanical parts with core charges are sent out to rebuilders who its components in creating rebuilt parts for resale. We are able to sell parts for less if we get a rebuildable core in exchange; if you bring in the part at the time of sale there is no core charge, if you don't have it with you the core charge is a deposit until you bring your old part in at which time you will be refunded the core charge. It also ensures the part is recycled properly instead of leaking hazardous fluids in a landfill.