Full Opinion (html_with_citations)

McCLANAHAN, Judge.

Eric Amir Ghameshlouy was convicted of a misdemeanor in violation of City of Virginia Beach Code § 23-7.1. On appeal, appellant seeks to challenge the trial court’s interpretation and application of this local ordinance. Appellant, however, did not perfect an appeal of the misdemeanor conviction. He perfected an appeal only as to a state law felony conviction arising out of the same incident. We, therefore, conclude that this Court has no jurisdiction to hear an appeal on the misdemeanor conviction, and dismiss the appeal.

I.

The City of Virginia Beach charged appellant with a misdemeanor violation of City of Virginia Beach Code § 23-7.1 (failure to provide correct identification to a police officer), as set forth in appellant’s arrest warrant, entitled “Warrant of Arrest—Misdemeanor (Local).” At the same time, the Commonwealth charged appellant with three related offenses under state law (possession of cocaine (Code § 18.2-250); assault *50on a law enforcement officer (Code § 18.2-57(C)); and probation violation (Code § 19.2-306)). All three of these state law offenses were adjudicated pursuant to a plea agreement, dated July 24, 2007, which was executed by appellant and the parties’ counsel. A sentencing order on these three offenses was then entered on August 1, 2007.1 While the plea agreement did not indicate it was conditional, appellant and the Commonwealth have stipulated that the plea agreement was, in fact, conditional as to appellant’s guilty plea on the cocaine possession charge.

On July 31, 2007, appellant filed a notice of appeal with the clerk’s office of the circuit court. In the notice, appellant listed the circuit court case numbers assigned to each of the three state law offenses and the local misdemeanor offense. However, appellant did not identify the City of Virginia Beach as a party to the appeal. Rather, appellant named only the Commonwealth of Virginia as the prosecuting authority, as set forth in the style of the case. Appellant also named only the Commonwealth of Virginia as the appellee in his certificate to the notice of appeal (see Rule 5A:6(d)). Furthermore, appellant stated in the notice of appeal that he “hereby gives notice of his intention to appeal from a final judgment of the Circuit Court of the City of Virginia Beach, rendered ... on July 24 2007.” We find no order in the record dated July 24, 2007. July 24, 2007 is, instead, the date of appellant’s plea agreement on the three state law offenses, pursuant to which the *51circuit court entered the August 1, 2007 sentencing order, separate and apart from the July 30, 2007 sentencing order on appellant’s local misdemeanor conviction.

Appellant then petitioned this Court seeking a review of issues involving the state law felony conviction for cocaine possession (question presented number 1) and the local misdemeanor conviction (question presented number 2). A judge of this Court denied the petition challenging the state law conviction, pursuant to Code § 17.1-407(C) (procedure for one-judge review in a criminal case), after determining there was no merit in appellant’s argument that the trial court erred in denying his motion to suppress.

II.

We now dismiss that part of appellant’s appeal challenging his local misdemeanor conviction due to his failure to perfect an appeal as to that conviction. For such an appeal, appellant was required to name the City of Virginia Beach in the notice of appeal because the City, as the prosecuting authority on the local misdemeanor charge, was an indispensable party. Woody v. Commonwealth, 53 Va.App. 188, 196-200, 670 S.E.2d 39, 43-45 (2008) (holding that Amherst County was an indispensable party in an appeal challenging convictions under both state law and the Amherst County Code, thus requiring that the County be named as a party in appellant’s notice of appeal in order to perfect an appeal on the local law conviction).2 Appellant, however, did not name the City of Virginia Beach as a party in either the notice of appeal or the accompanying certificate of service—naming only the Commonwealth of Virginia. “[T]he failure to join an indispensable party is a jurisdictional defect that requires dismissal of the appeal.” Id. at 199, 670 S.E.2d at 45 (dismissing on jurisdictional grounds an appeal of a conviction under local law because appellant did not name the local authority in his *52notice of appeal) (citing Asch v. Friends of the Community of Mount Vernon Yacht Club, 251 Va. 89, 91, 465 S.E.2d 817, 818-19 (1996))3; see Roberson v. City of Virginia Beach, 53 Va.App. 666, 674 S.E.2d 569 (2009) (holding that the City of Virginia Beach was an indispensable party in an appeal challenging a conviction under the City of Virginia Beach Municipal Code, thus requiring that the City be named as a party in appellant’s notice of appeal in order to perfect an appeal on the local law conviction); Watkins v. Fairfax County Dep’t of Family Servs., 42 Va.App. 760, 766, 595 S.E.2d 19, 22 (2004) (“[A]n indispensable party must be named in the notice of appeal in order to properly perfect the appeal.”).

Appellant thus failed to file a timely notice of appeal of his local misdemeanor conviction as required under Rule 5A:6(a). That is to say, as to the misdemeanor conviction, a notice of appeal was not filed within 30 days of the final order entered upon the conviction; and the notice of appeal that appellant did file was “ ‘ “ineffective” and the appeal [was] never properly perfected’ ” as to that conviction. Woody, 53 Va.App. at 195, 670 S.E.2d at 43 (quoting Watkins, 42 Va.App. at 774, 595 S.E.2d at 26); see Vaughn v. Vaughn, 215 Va. 328, 329-30, 210 S.E.2d 140, 141-42 (1974) (holding that “appeal was not perfected according to law,” and was therefore “dismissed as improvidently awarded,” where notice of appeal named as *53appellee “Carolyn F. Vaughn, Administratrix of the Estate of Donald W. Vaughn, Jr.,” rather than naming “Carolyn F. Vaughn” in her individual capacity). In short, no notice of appeal was filed as to the misdemeanor conviction.4 Accordingly, this Court is without jurisdiction to review appellant’s misdemeanor conviction. Woody, 53 Va.App. at 195, 670 S.E.2d at 43 (Rule 5A:6(a) requirement is “mandatory” and “jurisdictional” (citations and internal quotation marks omitted)); Watkins, 42 Va.App. at 774, 595 S.E.2d at 26 (“[T]he failure to file a notice of appeal ... within the requisite 30-day period ... necessarily affects this Court’s authority to exercise [its] jurisdiction” over the subject matter of the appeal.); Zion Church Designers and Builders v. McDonald, 18 Va. App. 580, 583, 445 S.E.2d 704, 706 (1994) (“The time requirements for filing are mandatory, and failure of the appellant to file the notice of appeal timely requires dismissal of the appeal.”).

*54Furthermore, this jurisdictional defect was not waived, as appellant contends, as a result of the Commonwealth moving this Court to amend the caption of the case by adding the City of Virginia Beach as an appellee, and the City of Virginia Beach later purportedly joining in the Commonwealth’s brief, addressing the merits of the misdemeanor conviction.5 First, such an amendment “presupposes a valid instrument as its object.” Wellmore Coal Corp. v. Harman Mining Corp., 264 Va. 279, 283, 568 S.E.2d 671, 673 (2002). Because appellant did not file a notice of appeal as to the misdemeanor conviction, “there was nothing to amend.”6 Id. Second, it is axiomatic that the Commonwealth could not effect a waiver of the jurisdictional defect as to some other party, i.e., the City of Virginia Beach, by the Commonwealth filing a motion requesting that such party be added as an appellee to the pending appeal. Third, it is also self-evident that the City of Virginia Beach could not “join” in an appeal that did not exist.7

*55We also find no authority for a third party to unilaterally participate in a pending appeal in this Court or the Virginia Supreme Court, other than the authority of the United States and the Commonwealth to file a brief amicus curiae without the consent of the Court or counsel. See Rules 5:30 and 5A:23. For a third party to be recognized as a party to a pending appeal, such party must obtain the Court’s approval upon the party’s motion to intervene. See Bagwell v. International Union, 244 Va. 463, 473-74, 423 S.E.2d 349, 355 (1992), rev’d on other grounds, 512 U.S. 821, 114 S.Ct. 2552, 129 L.Ed.2d 642 (1994) (addressing for the first time “whether a party may intervene in the first instance on [an] appeal” to this Court). The City of Virginia Beach filed no such motion in this appeal.8

*56Finally, estoppel principles are not available to appellant, as the dissent contends, “to create appellate jurisdiction over an indispensable party which is not properly before the Court,” as the Virginia Supreme Court held in Aseh. Asch, 251 Va. at 93, 465 S.E.2d at 819.

For these reasons, we dismiss appellant’s appeal of his local misdemeanor conviction.

Dismissed.

. Neither the July 24, 2007 plea agreement nor the August 1, 2007 sentencing order addressed appellant’s misdemeanor charge. The plea agreement, in fact, originally included terms addressing the misdemeanor charge, but those terms were deleted by hand and initialed by counsel on the version of the agreement that was executed.

Unlike the three state offenses, appellant was convicted of the local misdemeanor offense in a bench trial. A sentencing order for this conviction was entered on July 30, 2007, and recites the "City” as the prosecuting authority in the style of the case. This order of conviction names "T. Murphy" as the "Attorney for the Commonwealth,” and does not name counsel for the City of Virginia Beach. It is undisputed, however, that the Office of the Commonwealth's Attorney for the City of Virginia Beach conducted appellant’s prosecution for both the local misdemeanor charge and the charges under state law.

. As in Woody, the instant case involved “simultaneous prosecutions— [those] on behalf of the Commonwealth ... and one on behalf of the [City of Virginia Beach]." Woody, 53 Va.App. at 198, 670 S.E.2d at 44.

. In Asch, the Virginia Supreme Court rejected both actual notice and estoppel as grounds for overcoming the jurisdictional defect of failing to name an indispensable party in the notice of appeal, explaining as follows:

We reject the respondents' contention that the Yacht Club should be treated as a party to this appeal because it had notice of the appeal. The mere fact that an indispensable party who was a litigant in the trial court has notice that an appeal has been perfected against another litigant is not sufficient to confer this Court's jurisdiction over the indispensable party against whom no appeal has been properly perfected.
We also find no merit in the respondents’ contention that the Yacht Club is estopped from denying it is a party to this appeal. In this instance, this Court will not permit the respondents to utilize estoppel principles in an attempt to create appellate jurisdiction over an indispensable party which is not properly before the Court.

Asch, 251 Va. at 93, 465 S.E.2d at 819.

. In addition to naming only the Commonwealth of Virginia as the prosecuting authority below and the appellee in his appeal, appellant also referenced in his notice of appeal only his plea agreement, which was limited to disposition of his state law charges, as the "final judgment" from which he was appealing. Appellant specifically stated that July 24, 2007 was the date of the "final judgment" from which he was appealing. July 24, 2007 was actually the date of appellant’s plea agreement on the state law charges. That reference, along with naming only the Commonwealth of Virginia as appellee, gave further explicit indication that appellant was not appealing his local misdemeanor conviction. In fact, as of July 24, 2007, appellant had not yet been tried on the local misdemeanor offense. Appellant was tried on the misdemeanor offense on July 30, 2007.

We note, in this regard, that this case is clearly distinguishable from Carlton v. Paxton, 14 Va.App. 105, 109-11, 415 S.E.2d 600, 602-03 (1992), where this Court rejected appellees' challenge to the appellant’s notice of appeal. Unlike this case, in Carlton, there were no consolidated cases below, the validity of an order of adoption was the only matter at issue, appellant named the correct adverse party in his notice of appeal, but in the notice appellant incorrectly identified the final order being appealed. Id. Further, appellees acknowledged "that there was never any question as to which order was being appealed.” Id. at 110 n. 2, 415 S.E.2d at 603 n. 2. On those facts, we held that dismissal of the appeal was not warranted "[bjecause appellant did in fact file a notice of appeal” in the case, and "the purpose of Rule 5A:6 was met." Id. at 111, 415 S.E.2d at 603.

. The Commonwealth indicated in its motion that "it should remain involved” in this appeal because of the potential for appellant to appeal to the Virginia Supreme Court this Court’s disposition of his appeal on the state law offenses. The Commonwealth then moved this Court to dismiss this appeal as to the local misdemeanor conviction because of appellant’s failure to name the City of Virginia Beach, an indispensable party, in appellant’s notice of appeal.

. In advocating appellant’s position, the dissent, like appellant, proceeds upon the erroneous premise that appellant filed a notice of appeal as to his misdemeanor conviction, but simply did so in a defective manner. That defect, the dissent then asserts, was later waived by the City of Virginia Beach when "the brief responding to the merits of [appellant's] argument was signed and filed jointly by an Assistant Attorney General and by Thomas M. Murphy, Deputy Commonwealth’s Attorney for the City of Virginia Beach.” Once again, because there was no appeal of appellant's misdemeanor conviction, any action purportedly taken on behalf of the City of Virginia Beach in the pending appeal on appellant’s state law conviction would have been a nullity visa-vis the misdemeanor conviction.

. We thus need not decide whether the jurisdictional defect presented in this case would have otherwise implicated waivable personal jurisdiction, see Board of Supervisors of Fairfax County v. Board of Zoning Appeals of Fairfax County, 271 Va. 336, 347-48, 626 S.E.2d 374, 381 (2006) (holding 30-day filing requirement for appeal of Board of *55Zoning Appeals decision to circuit court did not implicate circuit court's subject-matter jurisdiction, and was, therefore, waivable), or, on the other hand, implicated non-waivable subject-matter jurisdiction, see Bowles v. Russell, 551 U.S. 205, 206-15, 127 S.Ct. 2360,---, 168 L.Ed.2d 96 (2007) (holding that, because the 30-day time limit for filing a notice of appeal under Federal Rule of Appellate Procedure 4(a) was derived from a federal statutory mandate, non-compliance was a bar to the lower court's subject matter jurisdiction, which was not subject to "forfeiture or wavier to excuse [appellant's] lack of compliance”); see also Porter v. Commonwealth, 276 Va. 203, 229, 661 S.E.2d 415, 427 (2008) (subject matter jurisdiction cannot be waived by the parties).

. We disagree with the dissent that Browning-Ferns Indus, v. Residents Involved in Saving the Environment, 254 Va. 278, 492 S.E.2d 431 (1997), State Water Control Bd. v. Crutchfield, 265 Va. 416, 578 S.E.2d 762 (2003), and The Greif Companies v. Hensley, 22 Va.App. 546, 471 S.E.2d 803 (1996), support the proposition that failure to name a necessary party in an appeal to this Court may be waived. Browning-Ferris Indus, involved an appeal of a decision of the Virginia Department of Environmental Quality (DEQ) to grant a permit to Browning-Ferris Industries (BFI) for the building of a solid waste management facility. After DEQ granted the permit, a group of residents living near the proposed site appealed that decision to the circuit court, naming only DEQ in the appeal. Browning-Ferris Indus., 254 Va. at 281-82, 492 S.E.2d at 433. Our Supreme Court rejected DEQ's argument that the circuit court erred in denying its motion to dismiss the appeal based on the residents' failure to name BFI, a necessary party, as a party to the appeal. The Supreme Court did so, however, only upon finding that the circuit court had granted BFI “leave to intervene in the proceedings,” which rendered "moot” the circuit court’s denial of *56DEQ's motion. See Rule 3:14 (setting forth provisions for intervention of a new party in a civil proceeding in circuit court).

Like Browning-Ferris Indus., Crutchfield involved the failure of a petitioner to name a necessary party in an appeal of a state agency decision to circuit court. There, Crutchfield, a landowner, challenged the State Water Control Board's decision to issue a permit to Hanover County allowing the discharge of treated wastewater into a river running adjacent to Crutchfield’s property. Crutchfield, 265 Va. at 420, 578 S.E.2d at 764. When filing his petition for appeal to circuit court challenging the decision, Crutchfield failed to name the County, a necessary party, in the petition. Id. at 421, 578 S.E.2d at 764. The circuit court later granted Crutchfield's request for leave to amend his petition to add the County as a party. Id. In affirming the circuit court’s allowance of the amendment, the Virginia Supreme Court held that Rule 2A:4 (governing the notice requirements for an appeal to circuit court under Virginia's Administrative Process Act) did not compel the circuit court to reject Crutchfield's request and dismiss die appeal, as the Board contended. Id. at 424, 578 S.E.2d at 766. Instead, under the Supreme Court's interpretation of Rule 2A:4, it was a "matter subject to the court’s discretionary authority.” Id. (citing Browning-Ferris Indus., 254 Va. at 282-83, 492 S.E.2d at 433-34).

In Hensley, the Virginia Workers' Compensation Commission ordered St. Paul Fire and Marine Insurance Company (St.Paul) and Liberty Mutual Fire Insurance Company (Liberty Mutual), the respective carriers for the employer over the relevant time period, to share equally in the payment of compensation owed to the claimant. St. Paul appealed the commission's decision to this Court, naming only Liberty Mutual and the claimant as appellees in its notice of appeal. Hensley, 22 Va.App. at 548, 471 S.E.2d at 804. Before addressing the merits, we rejected Liberty Mutual’s argument that the appeal should be dismissed because St. Paul failed in its notice of appeal to name the employer as an appellee and to provide the corresponding information required by Rule 5A:ll(b)(notice of appeal from an order of the commission). Id. at 548-51, 471 S.E.2d at 804-06. Our ruling, however, was based on our determination that the employer and its counsel were, in fact, listed as appellants on St. Paul's notice of appeal, and, therefore, "[a]ll necessary parties” were before the Court as required. Id. at 551, 471 S.E.2d at 806.