California Code, Government Code - GOV § 11185

(a) If the witness named in the subpoena is a natural person, the person is not obliged to attend as a witness in any matter under this article at a place out of the county in which he or she resides, unless the distance is less than 75 miles from his or her place of residence.

(b) If the witness named in the subpoena is not a natural person and has an office within this state, the subpoena may provide that the testimony of the persons designated to appear on behalf of the witness, as described in subdivision (b) of Section 11184, shall be given in the county in which the witness named in the subpoena has its principal executive or business office in this state or within 150 miles of that location.

(c) If the witness conducts business in this state but does not reside or have an office within this state, the subpoena may provide that oral testimony shall be given at a location that is within 75 miles of the residence or executive or business office of the witness.

(d) If the witness does not reside, have an office, or conduct business in this state, the testimony shall be given and documents and other items produced at a location set by a court.

(e) The department head may require any person who resides or conducts business in this state to produce the documents and other items described in subdivision (e) of Section 11181 at a location in the county in which the department head or the Attorney General maintains an office.

(f) Nothing in this section prevents the department head and subpoenaed person from agreeing that testimony may be given or production made at any location.