California Code, Probate Code - PROB § 2215

(1) Any person required to be listed in the petition.

(2) Any creditor of the ward or conservatee or of the estate.

(3) Any other interested person.

(b)(1) If the court determines that the transfer requested in the petition will be for the best interests of the ward or conservatee, it shall make an order transferring the proceeding to the other county.

(2) In those cases in which the court has approved a change of residence of the conservatee, it shall be presumed to be in the best interests of the conservatee to transfer the proceedings if the ward or conservatee has moved his or her residence to another county within the state in which any person set forth in subdivision (b) of Section 1821 also resides. The presumption that the transfer is in the best interests of the ward or conservatee, may be rebutted by clear and convincing evidence that the transfer will harm the ward or conservatee.