*380There is a "strong presumption that courts should determine the jurisdiction of arbitrators." ( Sandquist v. Lebo Automotive, Inc. (2016)
FACTS AND PROCEDURAL BACKGROUND
I. Facts
A. The Contract
On August 19, 2009, Vivera, a company that sold diet pills and other health and beauty products online, signed an Adverting Insertion Order (Insertion Order) with Pinnacle Dream Media, a company that offered "internet advertising services."
The Insertion Order "incorporate[d] as though fully set forth herein" a Master Advertiser Agreement (Master Agreement) and provided a weblink to access the Master Agreement; a hard copy of the Master Agreement was not attached. The *59Master Agreement is a more comprehensive document designed to "govern the placement and delivery of advertising" set forth in Insertion Orders. Among other things, the Master Agreement provided that (1) "the Parties consent to have all disputes regarding this agreement resolved by binding arbitration," and that any "prevailing party in any Arbitration shall be entitled to an award of attorney fees and costs for such arbitration," and (2) "[a]ll payments are personally guaranteed by the individual executing the [Insertion Order] or secured by the assets of [Pinnacle Dream Media's customer]."
The Insertion Order was "Accepted" by Vivera and bears the printed name and signature of plaintiff Clayton Douglass (Douglass).
By April 2011, Vivera had an unpaid balance with Pinnacle Dream Media totaling $816,530.
B. The Arbitration Proceedings
In March 2014, defendant Serenivision, Inc. (Serenivision) filed a demand for arbitration against Vivera and Douglass seeking damages of $816,530 plus late penalties and interest. Serenivision had been doing business as Pinnacle Dream Media.
In April 2014, Douglass filed an answer in response to the demand. In his answer, Douglass admitted that he had signed the Insertion Order "as Vivera's representative," but denied any liability for Vivera's debt because he *382had "refused to" sign the Master Agreement and thus never "agree[d] to personally guarantee any amounts owed ... by Vivera." He also alleged that Vivera's products were "fraudulent," thereby rendering the Insertion Order unenforceable because its subject matter was unlawful.
In September 2014, Douglass appeared at a preliminary hearing before the arbitrator, at which time he reaffirmed he was "appear[ing] voluntarily and submit[ting] to the jurisdiction of this Arbitrator."
In early November 2014, Douglass wrote a letter to Serenivision's counsel. In that letter, Douglass explained that he was "voluntarily" appearing in the arbitration because he was "trying to avoid the additional time and expense" of litigating the same matter in "a federal lawsuit." Douglass then stated that he would "decline to participate in the arbitration" if Serenivision did not agree to post a bond to cover the costs of attorney's fees Douglass might collect, under the terms of the Master Agreement, as the prevailing party in the arbitration.
On February 18, 2015, just 19 days before the matter was set for an evidentiary hearing before the arbitrator, Douglass wrote a letter to the arbitrator: (1) relaying his prior statements to Serenivision that he would voluntarily participate in the arbitration only if Serenivision posted a bond; (2) informing the arbitrator that Serenivision had refused to post a bond; and (3) stating that "[a] bond is necessary for this action to proceed or for this tribunal to exercise jurisdiction." The arbitrator construed the letter as an expedited request for an order requiring Serenivision to post a bond, and denied that motion a week later.
On March 2, 2015, Douglass wrote the arbitrator a letter "terminat[ing] his voluntary appearance" before the arbitrator. Douglass explained that he had been "willing to participate in this arbitration" because it would be "more cost-efficient" than litigating "before a court"; indicated that his "voluntary appearance" had been "conditioned ... on the posting of a bond by [Serenivision]"; and declared that he would "no longer" participate because the arbitrator had not required a bond to be posted. Douglass proclaimed he would *60make no further appearances in the arbitration proceedings.
True to his word, Douglass did not appear at the evidentiary hearing a week later. The arbitrator allowed Serenivision to present its case, and Serenivision called witnesses and introduced documentary evidence.
On May 22, 2015, the arbitrator issued a written order. The arbitrator ruled that Douglass had consented to having the arbitrator decide the question of his own jurisdiction by participating in the arbitration proceeding for months *383as a way "to avoid defending a federal court lawsuit"; that the arbitrator had jurisdiction over Serenivision's claim because Douglass signed the Insertion Order, which incorporated the Master Agreement (and its arbitration clause) by reference; and that Douglass, under the terms of the Master Agreement, was liable as the guarantor of Vivera's debt to Serenivision, which with penalties, interest, attorney's fees, and costs came to a total of $1,755,050.34, with additional interest accruing at a rate of 10 percent as of March 10, 2015.
Douglass's counsel was served with this order on May 30, 2015.
II. Procedural Background
On October 2, 2015, 125 days after he was served with the arbitrator's order, Douglass filed a lawsuit against Serenivision (1) to vacate the arbitration award, (2) for declaratory relief, and (3) for $1 million in compensatory damages and for punitive damages on the ground that the Insertion Order and Master Agreement were illegal and hence subject to rescission.
On January 5, 2016, and again on April 7, 2016, Serenivision filed a petition to confirm the arbitrator's award.
Douglass filed a response to Serenivision's first petition on February 2, 2016. Contrary to what he pled in his answer to the arbitration demand, Douglass in his response claimed that (1) he never signed the Insertion Order, and offered testimony from a handwriting expert that the signature on the Insertion Order was not his; (2) he had no interest in Vivera whatsoever and just had a "partial interest in a company that processed payments to Vivera"; and (3) he had told the arbitrator from the outset that his participation in the arbitration was conditioned on Serenivision posting a bond.
In a 17-page minute order, the trial court granted Serenivision's petition to confirm the arbitration award and denied Douglass's competing claim to vacate it.
Douglass filed this timely appeal.
DISCUSSION
Douglass argues that the trial court erred in confirming the arbitrator's award. Serenivision asserts that we need not reach Douglass's challenge because his challenge to the award was untimely. We address the timeliness issue first.
I. Timeliness of Douglass's Challenge
"Any party to an arbitration in which an award has been made may petition the court to ... vacate [the arbitrator's] award" ( Code Civ. Proc., § 1285 ),
Douglass raises three arguments in response, none of which has merit.
First, he asserts that he was not properly served with the arbitrator's award on May 30, 2015. However, this assertion is directly contrary to the allegation in his petition that "the signed award was served on counsel for [Douglass] on May 30, 2015." This allegation is a "judicial admission" that Douglass "may not ... contradict[ ]." ( Minish v. Hanuman Fellowship (2013)
Second, Douglass contends he should be able to challenge the arbitrator's award because he asked the trial court to vacate the arbitrator's award in his timely response to Serenivision's first petition to confirm. To be sure, "[a] response to a petition" to confirm an award "may request the court to ... vacate the award" (§ 1285.2), but a response containing such a request *385is only timely if it is "served and filed not later than 100 days" after the responding party was served with a signed copy of the award (§ 1288.2). (Accord, Eternity Investments, Inc. v. Brown (2007)
Lastly, Douglass argues that he is challenging the arbitrator's jurisdiction and such a jurisdictional challenge may be raised at any time, including for the first *62time on appeal. For support, he-like the trial court-cites the following language from National Union : "Subject matter jurisdiction, in this case meaning the arbitrators' authority or power to adjudicate a certain type of fee dispute, cannot be conferred by consent, waiver, or estoppel." ( National Union , supra , 235 Cal.App.3d at pp. 1723-1724,
Of course, parties may not confer subject matter jurisdiction upon a court by consent, waiver, or estoppel because our jurisdiction is defined by our Constitution or our Legislature, not by litigants. ( People v. Chadd (1981)
For these reasons, Douglass's petition to vacate was untimely.
II. Propriety of Order Confirming Arbitration Award
Douglass's challenge to the trial court's order confirming the arbitration award entails three analytically distinct questions: (1) did the parties consent to have the arbitrator decide whether the Master Agreement's arbitration clause applies to Serenivision's demand?; (2) if so, did the arbitrator decide that question correctly?; and (3) if so, did the arbitrator exceed his powers in ultimately concluding that Douglass owed Serenivision more than $1.7 million? We will address each issue separately. In so doing, we review the trial court's order de novo and its factual findings for substantial evidence. ( ECC Capital Corp. v. Manatt, Phelps & Phillips, LLP (2017)
A. Was the Arbitrator the Proper Person to Decide Whether the Arbitration Clause Applies to This Dispute?
Arbitration "is ... a matter of contract between the parties" ( First Options , supra , 514 U.S. at p. 943,
"When deciding whether the parties agreed to arbitrate a certain matter (including arbitrability [itself] ), courts generally ... should apply ordinary state-law principles that govern the formation of contracts." ( First Options , supra , 514 U.S. at p. 944,
Applying these principles, parties may expressly agree to arbitrate: (1) in a contract signed before an dispute arises, although they always retain the power to mutually broaden or narrow the scope of their earlier agreement ( Greenspan v. LADT, LLC (2010)
Alternatively, and most pertinent here, parties may enter into an implied in fact agreement to arbitrate through their conduct (which may additionally be deemed to estop them from denying such an agreement). (See Cabrera v. Plager (1987)
Whether a party's conduct constitutes consent is necessarily fact specific, and this case presents the question: Has a party clearly and unequivocally consented to have an arbitrator decide whether a dispute is subject to arbitration when that party: (1) files an answer that does not object to the arbitrator's power to decide that issue; (2) tells the arbitrator that he is "voluntarily" "submit[ting]" to the arbitral forum to avoid the higher cost of litigating issues in federal court; (3) appears, again without objection, at multiple prehearing conferences; (4) formally asks the arbitrator to impose a bond on the opposing party; and (5) only after the arbitrator refuses to require a bond, and on the eve of the evidentiary hearing, purports to rescind his voluntary participation on the ground that a bond was a condition precedent to his participation? We conclude that the answer is "yes," and do so for three reasons.
First, Douglass's conduct establishes, under the above-cited precedent, his consent to have the arbitrator decide which disputes are arbitrable. Although Douglass did not litigate in the arbitral forum to the point of submitting the issue to the arbitrator, he willingly and without objection participated in the arbitration proceedings for over 10 months (from April 2014 when he filed his answer to March 2015 when he withdrew from the arbitration proceedings); he availed himself of the arbitrator's authority when he asked the arbitrator to issue an order requiring Serenivision to post a bond; and he purported to rescind his voluntarily participation a few weeks before the evidentiary hearing and only after the arbitrator issued a ruling he did not like. What is more, Douglass's participation in the arbitration was no accident. As he told both the arbitrator and Serenivision, he was making a conscious and tactical decision to participate in the arbitration forum because it was cheaper. We also note that he was seeking to avail himself of the *389attorney's fees award only available in the arbitral forum; indeed, he was seeking a bond specifically in anticipation of such an award. This extent of voluntarily participation in an arbitration *65where one of the primary issues is whether the dispute was arbitrable, without any objection or reservation and done for tactical reasons, constitutes clear and unmistakable evidence of Douglass's consent to have the arbitrator decide that issue. (Accord, International Film , supra , 152 Cal.App.3d at p. 706,
Second, allowing Douglass to back out of the arbitral forum on the proverbial eve of the evidentiary hearing runs afoul of the principle that "[a] claimant may not voluntarily submit his claim to arbitration, await the outcome, and if the decision is unfavorable, challenge the authority of the arbitrator to act." ( University of San Francisco Faculty Assn. v. University of San Francisco (1983)
Third, our conclusion that Douglass's conduct in this case qualifies as consent affirms that the test for waiving resolution of an issue in a judicial forum by conduct fits where it should in the hierarchy of tests used to evaluate waiver of other fora through one's conduct. By their conduct, litigants can waive their right to litigate in an arbitral forum ( Christensen v. Dewor Developments (1983)
However, the tests for waiver by conduct in these different contexts vary in their stringency, and do so for policy reasons. The test for assessing whether a party, through her conduct in litigating in a judicial forum, has thereby waived her right to litigate an in arbitral forum is the most stringent, and the onerousness of this test implements the " ' "strong public policy in favor of arbitration as a speedy and relatively inexpensive means of dispute resolution." ' " ( St. Agnes , supra , 31 Cal.4th at p. 1204,
Douglass's conduct constitutes a waiver under this test because he substantially invoked the machinery of the arbitral forum in asking the arbitrator for relief, delayed until the eve of the evidentiary hearing his proclamation that his voluntary participation was conditional, and purposefully availed himself of the cheaper arbitral forum until the arbitrator made a ruling he did not like. Were we nevertheless to conclude that Douglass's conduct did not constitute a waiver of his right to a judicial forum, we would make the test for waiving a judicial forum more onerous than the test for waiving an arbitral forum, and would consequently upset the carefully crafted, policy-based hierarchy for evaluating when one's conduct waives the right to litigate in a particular forum.
*391Douglass offers three arguments in response.
First, he asserts that the never signed the Master Agreement, that the Master Agreement was never incorporated by reference into the Insertion Order, and that he never signed the Insertion Order. Even if we accept these assertions as true, they are irrelevant to our conclusion that Douglass has, by virtue of his subsequent conduct before the arbitrator alone , consented to having the arbitrator decide the issue of arbitrability.
Second, Douglass argues that his consent to having the arbitrator decide the question of arbitrability was conditioned on Serenivision posting a bond, and this condition was never met. To be sure, parties may make their promises conditional on the occurrence of a condition precedent ( Civ. Code, § 1439 ; Alki Partners, LP v. DB Fund Services, LLC (2016)
Lastly, Douglass contends that he sufficiently preserved his objection to the arbitrator's power to decide the question of arbitrability because he registered objections to his participation from the outset. As noted above, a party's participation in an arbitral forum does not constitute a waiver if it is preceded by an objection. ( International Film , supra , 152 Cal.App.3d at p. 706,
In sum, the arbitrator had the power to decide whether the disputes before him were subject to arbitration.
B. Did the Arbitrator Err in Concluding That This Dispute is Subject to Arbitration?
Where, as here, the parties have agreed to have the arbitrator decide whether their dispute is subject to arbitration, "the court's standard for reviewing the arbitrator's decision about that matter should not differ from the standard courts apply when they review any other matter that the parties have agreed to arbitrate." ( First Options , supra , 514 U.S. at p. 943,
We conclude that the arbitrator did not exceed his powers in determining that the arbitration clause in the Master Agreement reaches this dispute. That clause makes "all disputes regarding" the Master Agreement subject to "binding arbitration." The Master Agreement, including the arbitration clause, is incorporated by reference into the Insertion Order. One contract may incorporate the terms of another ( Avery v. Integrated Healthcare Holdings, Inc. (2013)
Douglass's various arguments to the contrary lack merit. He argued to the arbitrator that he never signed the Master Agreement (and argued to the trial court that he refused to sign the Master Agreement), but his signature on the Master Agreement is unnecessary to incorporate its terms because he signed and thereby affirmatively "accepted" the terms of the Insertion Order, which expressly incorporated the Master Agreement's provisions. Douglass argued to the trial court that he never signed the Insertion Order and never received a copy of the Master Agreement. Of course, the arbitrator could not have erred in not considering an argument never presented to him. Moreover, these arguments either directly contradict what Douglass told the arbitrator (namely, that he did sign the Insertion Order)
C. Did the Arbitrator Err in Concluding That Douglass was Liable as a Guarantor for Vivera's Unpaid Balance on the Insertion Order?
The only pertinent basis for overturning the arbitrator's award in this case is that the arbitrator "exceeded [his] powers." (§ 1286.2, subd. (a)(4).) It is well settled, however, that an arbitrator does "not exceed [his] powers merely by erroneously deciding a contested issue of law or fact." ( Advanced Micro Devices, Inc. v. Intel Corp. , supra , 9 Cal.4th at p. 366,
The arbitrator did not commit any errors of law or fact, let alone exceed his powers. As discussed above, the terms of the Master Agreement were incorporated into the Insertion Order. The Master *69Agreement provides that "[a]ll payments are personally guaranteed by the individual executing the" Insertion Order. Because Douglass admitted that he signed the Insertion *394Order and thereby accepted its terms, he "executed" that Order and is contractually bound as a guarantor of Vivera's outstanding debt. (See Transdyn/Cresci JV v. City and County of San Francisco (1999)
DISPOSITION
The judgment is affirmed. Serenivision is entitled to its costs on appeal.
We concur:
LUI, P. J.
CHAVEZ, J.
The court denied as moot Serenivision's demurrer to Douglass's complaint.
All further statutory references are to the Code of Civil Procedure unless otherwise indicated.
This admission renders irrelevant Douglass's challenge to the admissibility of additional evidence that he was the signatory to the Insertion Order.