While a court’s lack of fundamental jurisdiction can be challenged at any time, an argument that a court ruled in excess of jurisdiction is subject to forfeiture if not timely asserted. Appellant pleaded guilty to a drug offense and the court sentenced him to the mid term, but suspended execution of the sentence, and placed him on probation. The prosecutor then filed a motion to revoke probation based on newly committed offenses. Pursuant to a negotiated disposition, appellant admitted the probation violation on condition that probation be reinstated. But, as part of the deal, appellant agreed the trial court could increase his sentence for the drug offense from the mid term to the upper term. The execution of the sentenced remained suspended, and appellant did not appeal. The prosecutor filed a second motion to revoke probation based on the commission of yet another new offense. After a contested hearing, the court revoked appellant’s probation and executed the previously suspended upper-term sentence to which appellant had agreed after the first violation. Appellant then appealed, arguing the court lacked the jurisdiction to increase the previously executed but suspended sentence. The Court of Appeal found the claims were forfeited. Although the trial court lacked the authority to increase appellant’s sentence (In re Howard (1997) 16 Cal.4th 1081; Pen. Code, § 1203.2, subd. (c)), this was an act in excess of its jurisdiction, not a lack of fundamental jurisdiction because the court had jurisdiction over the parties and the subject matter. By failing to timely appeal from that order, the challenge was forfeited. Also, because appellant consented to the increased sentence, he is estopped from complaining about it. (People v. Hester (2000) 22 Cal.4th 290.)