delivered the opinion of the court:
We must determine whether we have jurisdiction to consider the defendant’s appeal of the trial court’s first-stage dismissal of her post-conviction petition as frivolous and patently without merit. The People contend that the appeal must be dismissed because the defendant filed her postconviction petition in the trial court after the expiration of the limitations period established by section 122—1(c) of the Post-Conviction Hearing Act (the Act) (725 ILCS 5/122—1(c) (West 1996)) and failed to allege any facts showing that the delay was not due to her culpable negligence. We agree with the People, and we therefore dismiss the appeal.
FACTS
After a bench trial in 1990, the defendant was convicted of four counts of unlawful delivery of a controlled substance and was' *289sentenced to concurrent terms of 6, 10 and 24 years’ imprisonment. The judgment of the trial court was affirmed on direct appeal. People v. Caraballo, 231 Ill. App. 3d 685 (1992).
The defendant filed a petition for postconviction relief on April 22, 1997. In her petition, the defendant made no allegations of fact showing that any delay in filing her petition was not due to her culpable negligence. After the trial court dismissed the petition as frivolous and patently without merit on May 1, 1997, the defendant filed the instant appeal. The People moved to dismiss the appeal, contending that this court lacks jurisdiction because the defendant’s postconviction petition was time-barred. After first granting the People’s motion, we allowed the defendant’s petition for reconsideration and invited the parties to submit supplemental arguments on the issue of jurisdiction.
DISCUSSION
The statute of limitations applicable to the filing of the defendant’s postconviction petition was the statute that was in effect at the time she filed her petition. See People v. Bates, 124 Ill. 2d 81, 85-86 (1988) (amendment to the Act that shortened the statute of limitations should be applied retroactively to a conviction that occurred prior to its enactment). When the defendant filed her postconviction petition on April 22, 1997, the Act provided, inter alia, as follows:
“No proceedings under this Article shall be commenced more than 6 months after the denial of a petition for leave to appeal or the date for filing such a petition if none is filed or *** 3 years from the date of conviction, whichever is sooner, unless the petitioner alleges facts showing that the delay was not due to his or her culpable negligence.” 725 ILCS 5/122—1 (c) (West 1996).
Judgment on the defendant’s convictions was entered on November 5, 1990. Her direct appeal was decided on July 21, 1992. No petition for leave to appeal to our supreme court was filed by the defendant. As the People point out, the defendant’s postconviction petition was filed more than four years late under the governing statute. Therefore, the People maintain, this court lacks jurisdiction to consider the defendant’s appeal.
In response, the defendant argues that the filing of a notice of appeal is the only jurisdictional step in the appellate process. People v. Jones, 104 Ill. 2d 268, 283 (1984). She maintains that the statute of limitations is an affirmative defense and is not at issue until it is raised by the People in its answer to the petition or in a motion to dismiss. Citing People v. Gaultney, 174 Ill. 2d 410, 419 (1996), the defendant contends that since the Act does not authorize the filing of motions to dismiss during the first stage of the postconviction proceedings, “[cjertainly, they are prohibited the same in a first-stage ap*290peal.” Therefore, according to the defendant, the People can raise the issue of timeliness only during the second stage of postconviction proceedings in the trial court. We disagree with the defendant’s analysis.
This court recently upheld a trial court’s sua sponte dismissal of a postconviction petition in the first stage on the ground that it was untimely. People v. Stenson, 296 Ill. App. 3d 93, 96 (1998). Other courts have similarly upheld first-stage dismissals on the basis of untimeliness. For example, in People v. McClain, 292 Ill. App. 3d 185, 186-87 (1997), the pro se defendant accompanied his untimely postconviction petition with a motion to file his petition late, asserting that the delay was not the result of his culpable negligence but, rather, was due to a lock-down at his prison and his inability to engage private counsel to assist him. The appellate court affirmed the trial court’s determination that the facts alleged by the defendant were not sufficient to excuse the late filing and its dismissal of the petition as untimely at the first step. McClain, 292 Ill. App. 3d at 188-89.
It is well settled that a defendant’s failure to file a postconviction petition within the limitations period established in the Act is a jurisdictional bar to his or her action. People v. Heirens, 271 Ill. App. 3d 392, 402 (1995). Likewise, where a statute creates a substantive right unknown at common law and provides the time within which the action must be commenced, failure to commence the action within the prescribed period is a jurisdictional bar to relief. Stenson, 296 Ill. App. 3d at 95. Subject matter jurisdiction cannot be waived, stipulated to, or consented to by the parties; the lack of subject matter jurisdiction can be raised at any time, in any court, directly or collaterally, by the parties or on the court’s own motion. Stenson, 296 Ill. App. 3d at 95.
The People contend that in People v. Reed, 42 Ill. 2d 169 (1969), our supreme court held that a postconviction petition was time-barred when the petitioner made no factual allegations showing that his failure to file the petition in a timely manner was not due to his culpable negligence. Because the record demonstrates that the instant defendant’s postconviction petition also contained no such allegations of lack of culpable negligence, the People maintain that we should dismiss the instant petition based upon the jurisdictional statutory limitations period, regardless of the actual basis for the trial court’s ruling. See People v. Nash, 173 Ill. 2d 423, 432 (1996) (holding that a judgment may be sustained on any ground warranted by the court regardless of the reasons relied upon by the trial court).
We are convinced, from our review of the governing statute and the relevant authority, that an untimely postconviction petition is *291fatally flawed if it fails to contain any allegations that the delay was not due to the petitioner’s culpable negligence. The plain language of the Act requires the dismissal of a postconviction petition filed untimely, unless the petitioner “alleges facts showing that the delay was not due to his or her culpable negligence.” The Act clearly places a burden upon the petitioner at the outset to allege facts establishing his or her lack of culpable negligence.
We also note several cases in which a first-stage dismissal of a postconviction petition as untimely has been upheld. See, e.g., McClain, 292 Ill. App. 3d 185; People v. Villanueva, 174 Ill. App. 3d 791 (1988) (defendant’s untimely pro se petition containing allegations found not sufficient to justify delay properly dismissed as untimely); People v: Robinson, 140 Ill. App. 3d 29 (1986) (defendant’s pro se petition properly dismissed at first stage as not timely filed when no facts were alleged to show delay was not due to defendant’s culpable negligence); see also People v. Bates, 124 Ill. 2d 81 (1988).
We find Bates most instructive on this issue. In Bates, the defendant filed his pro se postconviction petition 11 years after his conviction, which was five weeks after the time period in which to file such petitions had been reduced from 20 years to 10 years. The circuit court applied the new time limit and dismissed the petition as untimely. Bates, 124 Ill. 2d at 83. Our supreme court considered the issue of retroactivity of the statute shortening the period of time available for filing of the postconviction petition, holding that the shortened period did apply to the defendant. The court then went on to note that the defendant’s cause was not instantaneously barred by the enactment of the shortened limitations period, citing the language of the Act, which remained unchanged, that no proceeding shall be commenced beyond the applicable limitations period unless the petitioner alleges facts showing that the delay was not due to his or her culpable negligence, and holding:
“To avoid its effect, he need only have alleged facts justifying the delay in filing. Because his petition was not accompanied by any such allegations, we find that his petition must be dismissed as untimely.” (Emphasis added.) Bates, 124 Ill. 2d at 88.
As the statute and case law make clear, we hold that the burden is on the petitioner to make the required showing in the petition and the failure to do so will result in a dismissal. We find that the Act requires that the exceptions to the period of limitations must be pleaded at the outset. The appeal is dismissed for lack of jurisdiction.
Appeal dismissed.