California Code, Elections Code - ELEC § 2031

If a person has more than one residence and that person maintains a homeowner's property tax exemption on the dwelling of one of the residences pursuant to Section 218 of the Revenue and Taxation Code, there shall be a rebuttable presumption that the residence subject to the homeowner's property tax exemption is that person's domicile. However, this presumption shall not apply in the event any other residence is listed as the person's current residence address on any driver's license, identification card or vehicle registration issued to that person by, and on file with, the Department of Motor Vehicles.

If a person has more than one residence and that person claims a renter's tax credit for one of the residences pursuant to Section 17053.5 of the Revenue and Taxation Code, there shall be a rebuttable presumption that the residence subject to the renter's tax credit is that person's domicile. However, this presumption shall not apply in the event any other residence is listed as the person's current residence address on any driver's license, identification card, or vehicle registration issued to that person by, and on file with, the Department of Motor Vehicles.

This section shall not be applicable to state or federal elected officials.