OPINION
¶ 1 Cоpper Hills Enterprises, Ltd. (“Taxpayer”) appeals the dismissal of the Arizona Department of Revenue (“ADOR”) as a party to this action, and further appeals the adverse grant of summary judgment on Taxpayer’s claim for refund of transaction privilege taxes paid to the City of Globe (“the City”). For the following reasons, we affirm the dismissal of ADOR, but rеverse the remainder of the judgment and remand for further proceedings.
FACTS AND PROCEDURAL BACKGROUND
¶ 2 Taxpayer operates the Copper Hills Hotel, Restaurant, Bar, and Gift Shop in Gila County. The business is located in “Gila County Island,” an unincorporated area between the City and the Town of Miami. On July 23, 1996, the City attempted to annex Gila County Island with the passage of Ordinance No. 677. From September 1996 to December 1998, Taxpayer paid the City $98,041.20 in municipal transaction privilege tax, which is a tax on gross receipts from taxable activity. See S. Pac. Transp. Co. v. Ariz. Dep’t of Revenue,
¶ 3 Subsequently, the Town of Miami successfully challenged the annexation. See Town of Miami v. City of Globe,
¶ 4 Taxpayer then filed two refund claims seeking a total of $98,041.20. ADOR administered the claims on the City’s bеhalf in accordance with an intergovernmental agreement. An administrative law judge issued a ruling in Taxpayer’s favor, but that ruling was reversed on appeal by the ADOR director, who found that the date from which the annexation was void “was not actually litigated” in Town of Miami and that annexation jurisdiction existed between August 22, 1996 and November 2, 1999. Taxpayer appealed to the tax court, naming both ADOR and the City as defendants. ADOR successfully moved to dismiss itself from the lawsuit, arguing that the complaint failed to state a claim against ADOR upon which relief could be granted.
¶ 5 Taxpayer and the City then filed cross-motions for summary judgment in the tax court, which entered summary judgment in the City’s favor. This appeal followed.
STANDARD OF REVIEW
¶ 6 Summary judgment is warranted when “there is no genuine issue as to any material fact and [] the moving party is entitled to a judgment as a matter of law.” Ariz. R. Civ. P. 56(c)(1). This court reviews a grant of summary judgment de novo. Wilderness World, Inc. v. Ariz. Dep’t of Revenue,
DISCUSSION
Authority To Levy The Transaction Privilege Tax
¶ 7 A municipality’s taxation jurisdiction is distinct from its ability to assert police power over an area because taxation and police power derive from separate legislative grants. See generally, City of Flagstaff v. Assoc. Dairy Prods. Co.,
¶ 8 A.R.S. § 9471(D) provides the following:
The annexation shall become final after the expiration of thirty days from the adoption of the ordinance annexing the territory by the city or town governing body, provided the annexation ordinance has been finally adopted in accordance with procedures established by statute, charter provisions or local ordinаnces, whichever is applicable, subject to the review of the court to determine the validity thereof if petitions in objection have been filed.
(Emphasis added).
A city or town shall file in the office of the county recorder ... a blank petition ... setting forth a dеscription and an accurate map of all the exterior boundaries of the territory contiguous to the city or town proposed to be annexed!.]
A.R.S. § 9471(A)(1). Finally, that statute provides:
Territory is not contiguous for the purposes of subsection A, paragraph 1 of this section unless:
3. The distance from the existing boundary of the annexing city or town where it adjoins the annexed territory to the furthest point of the annexed territory from such boundary is no more than twice the width of the annexed territory.3
See A.R.S. § 9471(H). Thus, Arizona law requires that the territory to be annexed must be “contiguous” to the annexing city, as that term is defined in A.R.S. § 9471(H). Arizona courts have required strict compliance with this procedure. See Town of Miami,
¶ 9 The City’s argument that the annexation beсame final hinges on the premise that it complied with all applicable procedures, including the procedures required by A.R.S. § 9471. That premise, however, is flawed. As Division Two of this court previously opined, “the method [the City] used to determine the parcel’s length/width ratio did not conform with the method required by [A.R.S.] § 9471(H)(3).”
¶ 10 Nonetheless, the City argues that during the subject period the purported annexation was effective for taxation purposes. We, however, hold that because the City lacked the necessary jurisdiction to undertake the annexatiоn, it was null and void.
¶ 11 In an analogous United States Supreme Court case, land owners contested the attempted annexation of noncontiguous lands by a town. Ocean Beach Heights,
¶ 12 The Arizona Supreme Court applied these principles in Gorman v. City of Phoenix, concluding that portions of the property to be annexed “were not contiguous to the City of Phoenix and that therefore the city commission is without jurisdiction to annex the territory involved.”
¶ 13 In reaching its holding, the Gorman court reasoned:
as a condition precedent tо the enactment of the ordinance in question the legislature required under the provisions of section 16-701, supra, that a petition be presented to the city commission signed by the owners of not less than one-half in value of the property in the area sought to be annexed as shown by the last assessment and that said area must be contiguous to the city.
Id. at 64,
¶ 14 Here, however, the City asserts that the subject taxation was authorized because a lower court recognized a period of annexation jurisdiction. The City reasons that the prior lower court judgment is res judicata as to the effectivenеss of the annexation and operates as law of the case. We disagree with that assertion.
¶ 15 Under the law of the case doctrine, an appellate court’s decision is controlling in both the lower courts and in subse
¶ 16 Here, Division Two of this court previously determined that the City had no jurisdiction to annex. Consequently, the annexation never took effect, and the trial court’s finding that it was effective for a period violates the law of the case doctrine. Therefore, the annexatiоn attempted here was a nullity and failed to support the City’s jurisdiction to tax. As the Arizona Supreme Court explained in Martin v. Whiting, a case concerning the boundaries of a school district, once an annexation is held void, it has “the effect of establishing that nothing had ever been done to change the boundaries of the High School District.”
¶ 17 Notwithstanding such authority, the City maintains that the trial court’s finding of a period of jurisdiction is not subject to collateral attack by Taxpayer. The Illinois Supreme Court, however, has recognized, and we agree, that a taxpayer can raise the issue of whether an annexation was legal when attacking the levy of municipal taxes. See People ex rel. Moyer v. Hausen,
REFUND OF ILLEGALLY COLLECTED TAX
¶ 18 The City next argues that even if the subject taxation was not valid, it need not issue a refund. Generally, of course, once a tax is held invalid under Arizona law, the government must refund the money collected. See Pittsburgh & Midway Coal Mining Co. v. Ariz. Dep’t of Revenue,
(1) Whether the decision establishes a new legal principle by overriding clear and reliable precedent or by deciding an issue whose resolution was not foreshadowed;
(2) Whether the retroactive application will further or retard operation of the rule, considering the prior history, purpose, and effect of the rule; [and]
(3) Whether retroactive application will produce substantially inequitable results.
Wilderness World,
¶ 19 None of these factors weigh in favor of withholding the refund here. No Arizona decision allows the City to retain taxes under these circumstances, and retroactive application of the hоlding will not retard the operation of an existing rule. Nor will any inequity result, because: (1) there was no prior consent to the levy and the failure to pay it would have subjected Taxpayer to penalties; (2) the City never quantified the alleged benefit to Taxpayer; (3) the City had the burden to undertake and complete the annexation and levy properly; and (4) Taxpayer was the only entity to sue for a refund, meaning that the City will retain all other money collected as a result its invalid annexation.
¶ 20 Another consideration in the Wilderness World analysis that undermines the City’s argument is the potential impact of a
DISMISSAL OF ADOR
¶21 Finally, Taxpayer appeals the dismissal of ADOR, arguing that ADOR is a necessary party to the action under the rules of joinder set forth in Arizona Rule of Civil Procedure 19(a). The Arizona Supreme Court articulated the joinder test as follows:
The test of indispensability in Arizona is whether the absent person’s interest in the controversy is such that no final judgment or decree could be entered, doing justice between the parties actually before the court and without injuriously affecting the rights of others not brought into the action.
Town of Gila Bend v. Walled Lake Door Co.,
¶ 22 The compulsory joinder of parties under Rule 19 entails a three-step anаlysis. The court must determine: (1) if complete relief can be accorded in the party’s absence; (2) whether there is a substantial risk that the existing parties could be subjected to multiple or inconsistent obligations; and (3) whether the absent party, if joinder is not feasible, is indispensable. Ariz. R. Civ. P. 19(a)(2); see Daniel J. McAuliffe & Shirley J. Wahl, 2 Civil Trial Practice § 10.10, at 223 (2d ed.2001).
¶ 23 Taxpayer seeks an award against the City in the amount of the refund and interest. Because the City can afford complete relief, ADOR is not a necessary party.
¶24 Taxpayer contends, however, that it has never been given assurances that the actual funds are in the City’s possession and not ADOR’s. But, as ADOR points out, this contention is irrelevant. It is undisputed that ADOR collected the municipal tax revenues оn the City’s behalf. The tax collection agreement obligates ADOR to pay the collected revenues to the City on a weekly basis. Because payment to the agent constitutes payment to the principal, as a matter of law, the City has received the disputed tax payments and is liable. See Ariz. Storage & Distrib. Co. v. Rynning,
¶ 25 Furthermore, we have found no law or rule requiring a taxpayer to join ADOR in a case that does not involve state tax issues. Indeed, ADOR’s aсtions in administering the tax were not relevant to the legal dispute. We therefore affirm the tax court’s dismissal of ADOR because the court was able to resolve the issue without its involvement.
CONCLUSION
¶ 26 For the reasons discussed above, we reverse and vacate the grant of summary
Notes
. Contrary to the City's argument, nothing in Arizona Revised Statutes ("A.R.S.”) section 9-471(D) (Supp.2006) requires a taxpayer to request injunctive relief. Nor do annexation statutes dictate the procedures for tax refund claims.
. We note that the 2006 amendments to A.R.S. § 9-471 are not relevant to this appeal.
. The Arizona Legislature amended the statute in 1997 to state that the territory’s length cannot be more than twice the maximum width of the annexed territory. 1997 Ariz. Sess. Laws, ch. 204, § 1.
. Pursuant to A.R.S. § 9-471(H), such territory is deemed to be not contiguous for the purposes of A.R.S. § 9-471(A)(l).
. While the City also contends that the doctrines оf estoppel and unjust enrichment bar the recovery of the taxes paid, it could not have reasonably relied on the legitimacy of the annexation, because the City of Miami litigation began even before the annexation order formally took effect. Consequently, no reliance or unjust enrichment could have occurred. See City of Delphi v. Startz-man,
