OPINION
Opinion by
The sole issue in this appeal is whether an agreed nunc pro tunc judgment rendered in a previous suit is valid and enforceable. Following a trial on agreed stipulated facts, the trial court ruled the nunc pro tunc judgment was enforceable and, based on that judgment, signed a new judgment awarding the County of Dallas Tax Collector, Dallas County Community College District, Parkland Hospital District, Dallas School Equalization Fund, City of Dallas, Dallas Independent School District, Dallas Education District, and Downtown Improvement District No. 1, (the “Taxing Authorities”) $34,000 in ad valorem taxes. The Roman Catholic Diocese of Dallas brings this appeal challenging the trial court’s ruling and arguing the agreed nunc pro tunc judgment is void and unenforceable because it attempts to correct a judicial error and changes the substance of the original judgment after the expiration of the trial court’s plenary jurisdiction. After reviewing the stipulated facts, we conclude the agreed nunc pro tunc judgment rendered in the previous suit is void. Accordingly, we reverse the *478 trial court’s judgment in this case and render judgment that the Taxing Authorities take nothing by their claim.
This cause arose out of a lengthy and involved series of suits concerning ad valo-rem property taxes allegedly owed by the Diocese for the years 1987 through 1992. Although the procedural history of these suits is complicated, the agreed factual stipulations presented to the trial court in this case are simple. The agreed stipulations filed by the parties state as follows: 1
1. In 1989 a lawsuit styled Bright Laughlin Office Partners and the Roman Catholic Diocese of Dallas v. Dallas Central Appraisal District and Dallas County Appraisal Review Board was filed in the 95th Judicial District Court of Dallas County.
2. As part of the subject lawsuit, on May 31, 1991, the parties to the action entered into an Agreed Judgment.... The May 31, 1991 Agreed Judgment assessed values on the subject property for tax years 1989-1991.
3. On February 24, 1992, the parties to the action submitted an Agreed Nunc Pro Tunc Judgment.... The February 24, 1992 Nunc Pro Tunc added assessments for tax years 1987 and 1988 (in addition to including tax years 1989, 1990 and 1991).
4. The Agreed Nunc Pro Tunc Judgment was presented to the Court by the parties without any additional evidence nor was a court reporter’s record created by the parties.
5. No appeal was taken by either party from either the May 31, 1991 Agreed Judgment ... or the February 24, 1992 Nunc Pro Tunc Judgment.
The Taxing Authorities brought this suit claiming, among other things, that the Diocese failed to pay ad valorem taxes for the years 1987 and 1988 as ordered by the agreed nunc pro tunc judgment. 2 The Diocese responds that the agreed nunc pro tunc judgment is void because it was signed outside the trial court’s plenary jurisdiction. Because the Diocese believes the nunc pro tunc judgment is void, it contends the trial court in this case erred by rendering a new judgment to enforce the terms of the nunc pro tunc judgment and ordering the Diocese to pay the additional two years of ad valorem taxes.
The standard of review in a case tried on agreed stipulated facts is de novo.
See Alma Group L.L.C. v. Palmer,
The stipulated facts, together with the attached judgments in this case, show that the agreed nunc pro tunc judgment was signed after the expiration of the trial court’s plenary jurisdiction over the original agreed judgment.
See
Tex.R. Civ. P. 329b. Because plenary jurisdiction had expired, the trial court could correct only clerical errors in the judgment.
See Escobar v. Escobar,
The original agreed judgment at issue in this case was submitted to the trial court as an agreed judgment by the parties pursuant to a compromise and settlement. The terms of the settlement were set forth in the agreed judgment and submitted to the trial court for its approval. Because the trial court approved the settlement by signing the agreed judgment, the judge’s act of signing the judgment constituted his rendition of the judgment.
Cf Wood v. Griffin & Brand of McAllen,
The agreed nunc pro tunc judgment signed approximately nine months after the original judgment purports to change the decretal portion of the original judgment by imposing an additional two years of tax liability on the Diocese. This is a substantive change that creates an obligation to pay where no such obligation previously existed.
See In re Marriage of Ward,
The fact that the nunc pro tunc judgment was agreed to by the parties does not affect the outcome in this case. It is well-settled that subject matter jurisdiction cannot be conferred by agreement.
See Morrow v. Corbin,
The Taxing Authorities also contend the trial court in this case did not
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have the authority to declare the agreed nunc pro tunc judgment void because the Diocese failed to meet the standards for an equitable bill of review. This case, however, was not brought as a bill of review. The challenge brought by the Diocese is in the nature of a collateral attack. A collateral attack may be used to set aside a judgment that is void or involves fundamental error.
See Texas Dept. of Transp, v. T. Brown Constructors, Inc.,
Finally, the Taxing Authorities contend the Diocese is barred from challenging the subject taxes because it failed to follow the proper processes or raise the proper defenses under the Texas Property Tax Code in the original suit. This argument is without merit because the Diocese is not challenging the legal correctness of the substance of the nunc pro tunc judgment. It is challenging the power of the trial court to render the judgment. A party may seek to enjoin the enforcement of a void judgment regardless of whether he has a good defense against the cause of action upon which the judgment was based.
See August Kern Barber Supply Co. v. Freeze,
Based on the foregoing, we conclude the trial court erred in enforcing the terms of the agreed nunc pro tunc judgment because the judgment was void as a matter of law. We reverse the trial court’s judgment in this case and render judgment that the Taxing Authorities take nothing by their claim.
Notes
. The portions of the stipulations concerning the attachment of exhibits have been omitted. Copies of both the May 31, 1991 Agreed Judgment and the February 24, 1992 agreed nunc pro tunc judgment were submitted as exhibits to the agreed stipulations.
. All other issues have been severed from this suit.
