A Core deposit is required on rebuilt parts to encourage you to return your original old part so that it can be rebuilt. Core deposits on some parts are very high because they are irreplaceable - if these cores are not returned, there may no longer be any available for rebuild in the future. Cores returned for credit must be accompanied by a copy of your invoice, and it must be exactly the same part as the one you received, complete and assembled, empty of fluids and reasonably clean. All cores must be free of any physical or accident damage, modifications or any other damage outside of normal wear-and-tear that may deem the core non-rebuildable. Any unacceptable core returned to Vertex will not be credited, nor will any shipping costs both inbound and outbound.