Cal. Civ. Code § [1488.]

Section Fourteen Hundred and Eighty-eight. An offer of performance must be made to the creditor, or to any one of two or more joint creditors, or to a person authorized by one or more of them to receive or collect what is due under the obligation, if such creditor or authorized person is present at the place where the offer may be made; and if not, wherever the creditor may be found.