Cal. Civ. Proc. Code § 631

(a) The right to a trial by jury as declared by Section 16 of Article I of the California Constitution shall be preserved to the parties inviolate. In civil cases, a jury may only be waived pursuant to subdivision (f).
(b) At least one party demanding a jury on each side of a civil case shall pay a nonrefundable fee of one hundred fifty dollars ($150), unless the fee has been paid by another party on the same side of the case. The fee shall offset the costs to the state of providing juries in civil cases. If there are more than two parties to the case, for purposes of this section only, all plaintiffs shall be considered one side of the case, and all other parties shall be considered the other side of the case. Payment of the fee by a party on one side of the case shall not relieve parties on the other side of the case from waiver pursuant to subdivision (f).
(c) The fee described in subdivision (b) shall be due on or before the date scheduled for the initial case management conference in the action, except as follows:
1. (1) In unlawful detainer actions, the fees shall be due at least five days before the date set for trial.
2. (2) If no case management conference is scheduled in a civil action, or the initial case management conference occurred before June 28, 2012, and the initial complaint was filed on or after July 1, 2011, the fee shall be due no later than 365 calendar days after the filing of the initial complaint.
3. (3) If the initial case management conference occurred before June 28, 2012, and the initial complaint in the case was filed before July 1, 2011, the fee shall be due at least 25 calendar days before the date initially set for trial.
4. (4) If the party requesting a jury has not appeared before the initial case management conference, or first appeared more than 365 calendar days after the filing of the initial complaint, the fee shall be due at least 25 calendar days before the date initially set for trial.
(d) If a party failed to timely pay the fee described in subdivision (b) that was due between June 27, 2012, and November 30, 2012, the party will be relieved of a jury waiver on that basis only if the party pays the fee on or before December 31, 2012, or 25 calendar days before the date initially set for trial, whichever is earlier.
(e) The parties demanding a jury trial shall deposit with the clerk or judge, at the beginning of the second and each succeeding day’s session, a sum equal to that day’s fees and mileage of the jury, including the fees and mileage for the trial jury panel if the trial jury has not yet been selected and sworn. If more than one party has demanded a jury, the respective amount to be paid daily by each party demanding a jury shall be determined by stipulation of the parties or by order of the court.
(f) A party waives trial by jury in any of the following ways:
1. (1) By failing to appear at the trial.
2. (2) By written consent filed with the clerk or judge.
3. (3) By oral consent, in open court, entered in the minutes.
4. (4) By failing to announce that a jury is required, at the time the cause is first set for trial, if it is set upon notice or stipulation, or within five days after notice of setting if it is set without notice or stipulation.
5. (5) By failing to timely pay the fee described in subdivision (b), unless another party on the same side of the case has paid that fee.
6. (6) By failing to deposit with the clerk or judge, at the beginning of the second and each succeeding day’s session, the sum provided in subdivision (e).
(g) The court may, in its discretion upon just terms, allow a trial by jury although there may have been a waiver of a trial by jury.
(h) The court shall transmit the fee described in subdivision (b) to the State Treasury for deposit in the Trial Court Trust Fund within 45 calendar days after the end of the month in which the fee is paid to the court.