California Code, Financial Code - FIN § 18234

An industrial loan company shall upon repayment of any loan in full, cancel or plainly mark “paid” and return to the borrower or person making final payment, the note evidencing the loan.  If such borrower is not otherwise obligated to such company, the company shall release all security for such loan, endorse and return any certificate of ownership, and return to the borrower any security agreement, assignment, or order signed by the borrower, except such as are a part of the court record in any action, or such as have been delivered to a third person for the purpose of carrying out the terms thereof.