DECLAN FLIGHT, INC.

v.

TEXTRON EAVIATION, INC.

Declan and RRA sued Textron and eAviation for tortiously interfering with their respective contracts with Pipistrel (Counts I and II), as well as with a separate sales agreement between RRA and Mesa Airlines for the purchase of Pipistrel aircraft (Count III). The district court dismissed the Plaintiffs&#x²⁷; claims based on their contracts with Pipistrel for forum non conveniens, concluding that the Defendants—despite not being a party to those contracts—could nonetheless enforce the contracts&#x²⁷; forum-selection clauses channeling litigation to Slovenia under the federal common law doctrine of equitable estoppel. As to RRA&#x²⁷;s claim alleging tortious

interference with the Mesa deal, the district court found that while RRA had adequately alleged personal jurisdiction over the Defendants it had failed to state a viable claim and dismissed this claim as well.

On appeal, the Plaintiffs argue that the district court erred by conducting its analysis under the modified forum non conveniens test announced by the Supreme Court in Atlantic Marine Construction Co. v. U.S. District Court for the Western District of Texas, 571 U.S. 49 (2013), which only applies when a valid forum-selection clause reaches the claims plead. In their view, the contracts&#x²⁷; forum-selection clauses are not applicable here because their contracts with Pipistrel are governed by Slovenian law, which does not recognize non-signatory enforcement under these circumstances. RRA also maintains that it plausibly alleged tortious interference with the Mesa sales contract in Count III. The Defendants cross-appeal the district court&#x²⁷;s finding of personal jurisdiction on that claim as well.

After careful review and with the benefit of oral argument, we reverse the dismissal of Counts I and II for forum non conveniens, reverse the district court&#x²⁷;s finding of personal jurisdiction as to Count III, and remand for further proceedings.

I. FACTUAL AND PROCEDURAL BACKGROUND¹

Appellant Declan Flight, Inc. (“Declan") is an Arizona corporation specializing in aviation management. Appellant Right

1 Because this case comes to us on a motion to dismiss, our discussion of the facts comes from the allegations in the second amended complaint.

Rudder Aviation, LLC (“RRA”) is a Florida limited liability company that works as a “full-service aerospace firm providing services such as airport management, flight training, maintenance facilities, aircraft sales and aircraft management.” From 2020 to 2022, Declan and RRA spearheaded sales in the U.S. market for Slovenian aircraft manufacturer Pipistrel d.0.0. (“Pipistrel"). At their peak, they managed 90% of Pipistrel&#x²⁷;s total sales. But in April 2022, Textron, Inc. (“Textron”) acquired Pipistrel and put Pipistrel under the control of its newly incorporated subsidiary, Textron eAviation, Inc. ("eAviation"). Having integrated Pipistrel into their network of aircraft marketing and distribution, Textron and eAviation no longer had any need for Declan or RRA. So, despite its existing contracts with Declan and RRA, Pipistrel soon terminated those agreements, cutting Declan and RRA out of owed and expected commissions.

1. The Declan Contracts

On October 2, 2020, Declan entered into a contract with Pipistrel Vertical Solutions d.o.o. (“Pipistrel Vertical”), a Pipistrel subsidiary, to serve as an "independent entrepreneur” and chief sales representative for special products and engineering services in the United States (the “2020 Declan Contract”). Under the 2020 Declan Contract, Declan was “required to spearhead the sales of the Pipistrel products and provide sales support services.” In exchange, Declan would receive a monthly payment of €12,000, plus a 5% commission on all sales. The 2020 Declan Contract provided it

would expire on October 1, 2021, but that it could be renewed by mutual consent of the parties.

By all accounts, both Declan and Pipistrel were initially satisfied with their business relationship. Ivo Boscarol, Pipistrel&#x²⁷;s founder and chairman, told Declan about a year into their venture that Pipistrel was "really happy" with the firms&#x²⁷; cooperation and that he was "convinced" they "will be very successful together also in the future." Declan and Pipistrel Vertical renewed their agreement in November 2021 for the three-year term between January 1, 2022, and December³¹, 2024 (the “2022 Declan Contract"). The terms of the 2022 Declan Contract were similar to those of the prior agreement: Declan would continue to work for Pipistrel Vertical in a business-development and sales role; it would now receive a fixed hourly rate; and it would continue to receive a 5% commission on its sales and expense reimbursements for its services. A party could unilaterally terminate the contract only if the counterparty was late in complying, or failed to comply, with its contractual obligations and did not cure its breach within a reasonable time following notice thereof. The contract also would automatically terminate if "cooperation of the Contracting Parties becomes impossible in any way."

The 2022 Declan Contract contained the following forumselection provision:

Any controversial relations arising from this or in connection with this contract will be settled primarily by the contracting parties by mutual consent, otherwise

the dispute shall be settled by the court having jurisdiction over the seat of the Contracting Authority. The "Contracting Authority" refers to Pipistrel Vertical, which is headquartered in Slovenia.

2. The RRA Contract

On September²⁷, 2021, RRA contracted with Pipistrel and its subsidiary, Pipistrel Italia S.r.l, to be the exclusive U.S. distributor of several Pipistrel aircraft (the “RRA Contract”). The RRA Contract granted RRA the right to purchase these aircraft at discounted rates from Pipistrel before reselling them to customers, apportioning the discount as a "commission." Although the RRA Contract was originally set to run for two years, the parties later agreed that their business relationship would be “maintained . . . with no particular termination date as long as RRA performed in accordance with" its contractual obligations. The contract also included a forum-selection clause, which provided that, “[i]n case of dispute the courts of Nova Gorica, Slovenia shall have jurisdiction[,]” as well as a choice-of-law clause dictating that it was "governed by the laws of Slovenia."

3. Textron Acquires Pipistrel and Freezes Out Declan

Soon after inking the 2020 Declan Contract, John Wood, Declan&#x²⁷;s CEO and principal, connected executives at Pipistrel with Textron, a large aircraft manufacturer headquartered in Rhode Island, "to discuss opportunities and synergies between the two companies." Over the next seventeen months, Pipistrel and Textron held over thirty meetings to discuss a potential merger between the

two firms. On March¹⁷, 2022, Textron disclosed in public SEC filings that it intended to purchase Pipistrel and its subsidiaries for approximately €218,000,000, and informed investors of its plan to integrate Pipistrel into Textron&#x²⁷;s "global aircraft sales and support network."

Two days later, Rob Scholl, a senior vice president at Textron, informally offered Wood a director-level position at eAviation, which at the time was a "business unit of Textron" specializing in "sustainably powered flight." Wood reminded Scholl that the 2022 Declan Contract remained in effect through 2024 and that he intended to continue managing Declan&#x²⁷;s business with Pipistrel. On April 1, 2022, Textron formally incorporated eAviation as a new subsidiary corporation that would house the Pipistrel entities following the acquisition. Scholl became President and CEO of eAviation. The Textron-Pipistrel deal closed on April¹⁵, 2022, with Textron now owning a 90% stake in the Pipistrel companies.

With Pipistrel officially under Textron&#x²⁷;s corporate umbrella, Textron and eAviation sought to tie up the loose ends posed by Declan&#x²⁷;s preexisting contractual relationship with Pipistrel Vertical. On June⁶, 2022, Scholl invited Wood to eAviation&#x²⁷;s headquarters in Kansas under the pretense that Wood would be meeting with "the Textron Special Missions Team to discuss ways that Textron and Declan could work together" on new product lines. When Wood arrived on site, he was led into a conference room. To his surprise, he was greeted not by the Special Missions Team but by Scholl, who slid Wood a document on eAviation letterhead

purporting to terminate the 2022 Declan Contract. Scholl explained to Wood that “he was terminating [the 2022 Declan Contract] because . . . eAviation did not plan to sell the products Declan was marketing and that the purchase between Textron and Pipistrel was an asset sale.” Neither premise was true, it turned out, as Pipistrel continued to sell “the exact products Declan marketed" and the Textron-Pipistrel deal “was not an asset sale."

Scholl also shared with Wood a draft settlement agreement, which offered to pay Declan a lump sum of $100,000, in addition to approximately €230,000 in outstanding commissions. According to Declan, this payoff was "significantly less than what Declan was owed" in commissions. In exchange, Declan would have to release all claims that it had against the "Textron Parties," which Wood took to mean both Textron and eAviation. Wood did not accept Scholl&#x²⁷;s offer.

4. The Mesa Contract

RRA would soon suffer a similar fate as Declan. The day after Textron announced its intent to acquire Pipistrel, Pipistrel sent a memorandum to RRA explaining that it "d[id] not have plans to cancel any agreements” it had with distributors. Scholl also visited RRA&#x²⁷;s facility in Florida to assure RRA that eAviation intended "to build a strong relationship with RRA" and that RRA was "needed&#x²⁷; . . . for the continued future success of Pipistrel.”

Taking Scholl at his word, RRA continued marketing Pipistrel aircraft. Around this time, RRA was approached by Mesa Airlines, a regional airline operating out of Phoenix, Arizona, that was

interested in purchasing a fleet of Pipistrel Alpha Trainer aircraft through RRA. In a July¹³, 2022, email, Tadej Hozic, the Pipistrel sales representative who was coordinating the deal with RRA, informed RRA that Pipistrel would sell the planes to RRA at an 18% discount on the first fifty planes, and a 20% discount on the remaining planes. Prior to finalizing the sale, RRA arranged for a meeting with Gabriel Massey (Pipistrel&#x²⁷;s managing director and president), Scholl, and Mesa. In a follow-up email, Massey, allegedly at the behest of Scholl, expressed concern at the pricing structure. RRA informed Massey that Hozic had already confirmed the discount, and that Mesa had already obtained approval from its board to proceed forward with the transaction.

On August¹⁸, 2022, RRA executed a contract with Mesa Airlines for the sale of twenty-five Pipistrel Alpha Trainer planes, with the option of purchasing an additional seventy-five aircraft (the "Mesa Contract”). The Mesa Contract provided it was to be governed by Florida law, and that "any dispute or claim arising out of [it] shall be filed in the courts of Citrus County, FL." It also stated that "[a]ny dispute arising under, out of, or related in any way to this Agreement or the legal relationship between Seller and Purchaser will be adjudicated solely and exclusively in the Citrus County, Florida, USA,” that "[e]ach of the parties consent to the exclusive personal jurisdiction of these courts," and that "by signing this Agreement, [each] waives any objection to venue of these Florida courts."

Even though the Mesa Contract had been signed, Massey continued to pester RRA about the deal&#x²⁷;s pricing structure. Because RRA wanted to maintain its business relationship with Pipistrel, it remained willing to work with Massey to resolve these “issues." On August²⁹, Massey sent RRA a new proposed pricing structure and told RRA that Scholl also had ideas about how to restructure the Mesa Agreement. Massey&#x²⁷;s proposal "greatly reduced” RRA&#x²⁷;s commission from what was guaranteed in the contract and from what Hozic quoted RRA in July. As a condition to accepting the reduced commission, RRA told Massey that it wanted an immediate three-year extension of the RRA Contract, so that RRA could continue to pursue sales on behalf of Pipistrel “with assurance and confidence." Scholl and Massey told RRA that it would be granted the extension, and that RRA would receive a draft agreement by mid-September.

Behind the scenes, Scholl had begun renegotiating the Mesa Contract directly with Mesa. Mesa also reached out directly to Scott Donnelly, Textron&#x²⁷;s CEO, to “work out the details of the new contract between Pipistrel and Mesa Airlines for the 100 aircraft." Textron then directed Pipistrel "to negotiate and finalize a new agreement" with Mesa. RRA received the draft extension agreement on September²⁶, 2022. Much to RRA&#x²⁷;s dismay, it would no longer have exclusive rights, or even guaranteed rights, over the sale of Pipistrel aircraft under the terms of the new agreement. Rather than accept these terms, RRA engaged counsel and informed Pipistrel that it believed Pipistrel&#x²⁷;s interference with the Mesa deal constituted a breach of the RRA Contract. On

November¹¹, 2022, Pipistrel sent RRA a letter terminating the RRA Contract. Three weeks later, Massey forwarded Mesa a revised contract for the purchase of the Alpha Trainers, effectively vitiating the Mesa Contract and cutting RRA out of the deal.

Declan and RRA sued Textron and eAviation in the U.S. District Court for the Middle District of Florida for tortious interference, alleging the Defendants directed Pipistrel and Mesa to breach their contracts with Declan and RRA. After the Plaintiffs filed an amended complaint, the Defendants moved to dismiss. While that motion was pending, the Plaintiffs sought leave to amend their complaint a second time to "address shotgun pleading deficiencies." The district court allowed them to file a second amended complaint, admonishing them that any future shotgun pleadings would be "subject to dismissal with prejudice." In their second amended complaint—the operative complaint—the Plaintiffs assert three counts of tortious interference, with each respectively based on the 2022 Declan Contract, RRA Contract, and Mesa Contract.

The Defendants renewed their motion to dismiss, arguing that the second amended complaint should be dismissed as a shotgun pleading, for lack of personal jurisdiction, and for failure to state a claim. Additionally, they argued that the claims based on the Declan and RRA Contracts (Counts I & II) should be dismissed for forum non conveniens in light of those contracts&#x²⁷; designation of Slovenia as the appropriate forum.

The district court largely agreed. In reviewing the motion as to Counts I and II, the district court began by observing that both the Declan and RRA Contracts contained forum-selection clauses directing related litigation to be adjudicated in Slovenia. Although neither Textron nor eAviation was a party to those contracts, the district court found that they could nonetheless invoke the forumselection clauses against the Plaintiffs under the federal-common law doctrine of equitable estoppel, which "allows a nonsignatory to enforce the provisions of a contract against a signatory when the signatory relies on the terms of the contract to assert claims against the nonsignatory." See Bahamas Sales Assoc., LLC v. Byers, 701 F. 3d 1335, 1342 (11th Cir. 2012). The district court then concluded that Slovenia provided an adequate alternative forum for these claims and dismissed Counts I and II without prejudice under the doctrine of forum non conveniens.

On Count III, the district court was satisfied that the second amended complaint adequately plead personal jurisdiction over Textron and eAviation. Even so, the court concluded that the Plaintiffs had failed to state a claim for tortious interference based on the Mesa Contract. In its view, their response brief below did not rebut any of the “Defendants[&#x²⁷;] arguments that Count III fails to state a claim,” which the court took to mean that the Plaintiffs had "conceded” this claim. The court also expressed in a parting footnote that the second amended complaint was a shotgun pleading because it jointly plead claims against both Defendants without specifying "which of the defendants are responsible for which acts or omissions." See Weiland v. Palm Beach Cnty. Sheriff&#x²⁷;s Off., 792 F. 3d

1313, 1323 (11th Cir. 2015). Accordingly, the district court dismissed Count III with prejudice.

The Plaintiffs timely appealed the dismissal of the second amended complaint. The Defendants also timely filed a cross-appeal, challenging the district court&#x²⁷;s conclusion that it had personal jurisdiction over them as to Count III. We consider both the appeal and cross-appeal here.

II. STANDARDS OF REVIEW

We review the construction of a written contract, and the enforceability of a contract&#x²⁷;s forum-selection and choice-of-law provisions, de novo. Nat&#x²⁷;l Fire Ins. Co. of Hartford v. Fortune Constr. Co., 320 F. 3d 1260, 1267 (11th Cir. 2003); Lipcon v. Underwriters at Lloyd&#x²⁷;s, London, 148 F. 3d 1285, 1290–91 (11th Cir. 1998). Dismissals for lack of personal jurisdiction and failure to state a claim are also reviewed de novo, "accepting the allegations in the complaint as true." SkyHop Techs., Inc. v. Narra, 58 F. 4th 1211, 1222 (11th Cir. 2023) (citing Don&#x²⁷;t Look Media LLC v. Fly Victor Ltd., 999 F. 3d 1284, 1292 (11th Cir. 2021)). A district court&#x²⁷;s dismissal for forum non conveniens is reviewed for abuse of discretion, “and should be affirmed &#x²⁷;unless we find that the district court has made a clear error of judgment, or has applied the wrong legal standard.” AQuate II LLC v. Myers, 100 F. 4th 1316, 1320 (11th Cir. 2024) (quoting GDG Acquisitions, LLC v. Gov&#x²⁷;t of Belize, 749 F. 3d 1024, 1028 (11th Cir. 2014)).

III. ANALYSIS

The Plaintiffs challenge the dismissal of all three claims for tortious interference. Like the district court, we consider the

claims based on the Declan and RRA Contracts together before turning to RRA&#x²⁷;s claim based on the Mesa Contract.

A. Counts I & II

We begin with Counts I and II, which the district court dismissed for forum non conveniens in favor of the Slovenian forum identified in the Declan and RRA Contracts&#x²⁷; forum-selection clauses.

"Procedurally, the appropriate way to enforce a forum-selection clause pointing to a state or foreign forum is through the doctrine of forum non conveniens,” AQuate, 100 F. 4th at 1322 (quoting Atl. Marine, 571 U.S. at 60), which allows a district court to "decline to exercise its jurisdiction when a foreign forum is better suited to adjudicate the dispute,” Fresh Results, LLC v. ASF Holland, B.V., 921 F. 3d 1043, 1048 (11th Cir. 2019) (citing Kolawole v. Sellers, 863 F. 3d 1361, 1369 (11th Cir. 2017)). Usually, a district court will dismiss a suit for forum non conveniens only if the defendant can establish that "(1) an adequate alternative forum is available, (2) the public and private factors weigh in favor of dismissal, and (3) the plaintiff can reinstate his suit in the alternative forum without undue inconvenience or prejudice.” Tazoe v. Airbus S.A.S., 631 F. 3d 1321, 1330 (11th Cir. 2011) (quoting Leon v. Millon Air, Inc., 251 F. 3d 1305, 1311 (11th Cir. 2001)). But where “there is a valid forum-selection clause, &#x²⁷;the calculus changes.” AQuate, 100 F. 4th at 1322 (alterations adopted) (quoting Atl. Marine, 571 U.S. at 63). As the Supreme Court outlined in Atlantic Marine, under such circumstances the plaintiff "bears the burden of establishing that transfer

to the forum for which the parties bargained is unwarranted," and the district court "must deem the private-interest factors to weigh entirely in favor of the preselected forum.” 571 U.S. at 63–64. Under Atlantic Marine&#x²⁷;s modified test, a valid forum-selection clause "should be &#x²⁷;given controlling weight in all but the most exceptional cases," and "will almost always" merit dismissal for forum non conveniens in favor of the designated forum. AQuate, 100 F. 4th at 1322- 23 (quoting Atl. Marine, 571 U.S. at 63).

Here, neither Textron nor eAviation was a party to the Plaintiffs&#x²⁷; contracts with Pipistrel, and the Plaintiffs never explicitly agreed to adjudicate their claims against Textron or eAviation in Slovenia. Even so, the district court allowed the Defendants to invoke those clauses under the doctrine of equitable estoppel.

According to the district court, "[c]onsideration of whether to enforce a forum selection clause in a diversity jurisdiction case is governed by federal law . . . not state law.” P&S Bus. Machs., Inc. v. Canon USA, Inc., 331 F. 3d 804, 807 (11th Cir. 2003) (citation omitted). Equitable estoppel, a doctrine recognized in federal common law, "allows a nonsignatory to enforce the provisions of a contract against a signatory” when the signatory "relies on the terms of the contract to assert his or her claims against the nonsignatory” or when the signatory "raises allegations of interdependent and concerted misconduct by both the nonsignatory and one or more of the signatories to the contract.” Byers, 701 F. 3d at 1342 (citing MS Dealer Serv. Corp. v. Franklin, 177 F. 3d 942, 947 (11th Cir. 1999)). The district court found that the Plaintiffs&#x²⁷; claims satisfied either

condition, and thus allowed the Defendants to “enforce the forum selection clause[s]" included in the Declan and RRA Contracts against the Plaintiffs. Applying Atlantic Marine&#x²⁷;s modified test, the district court concluded that Slovenia provided an adequate and available forum and that the public interest factors did not weigh against that forum adjudicating the matter—and dismissed Counts I and II for forum non conveniens.

On appeal, the Plaintiffs argue that the district court erred by applying the Atlantic Marine test, believing that the forum-selections clauses are not applicable to their claims. In their view, whether the Defendants may invoke the forum-selection clauses is a matter of contractual interpretation governed not by federal common law but by the substantive law governing the contracts, which they maintain is the law of Slovenia. And because Slovenia law, they argue, only allows signatories to a contract to invoke its forum-selection clause, the Defendants cannot rely on the Declan and RRA Contacts&#x²⁷; forum-selection clauses here.

Whether federal common law governs both the enforceability and interpretation of a contract&#x²⁷;s forum-selection clause is one of first impression for our Court—and one that has divided our sister Circuits. Compare Albemarle Corp. v. AstraZeneca UK Ltd., 628 F. 3d 643, 650 (4th Cir. 2010) (applying federal law to both issues), and Manetti-Farrow v. Gucci Am., Inc., 858 F. 2d 509, 513 (9th Cir. 1988) (same), with Firexo, Inc. v. Firexo Grp. Ltd., 99 F. 4th 304, 324 (6th Cir. 2024) (rejecting application of federal law to interpretive issues), Collins v. Mary Kay, Inc., 874 F. 3d 176, 185 (3d Cir. 2017) (same),

Weber v. PACT XPP Techs., AG, 811 F. 3d 758, 770 (5th Cir. 2016) (same), Martinez v. Bloomberg LP, 740 F. 3d 211, 217 (2d Cir. 2014) (same), and Yavuz v. 61 MM, Ltd., 465 F. 3d 418, 430 (10th Cir. 2006) (same). Given that the "question of the scope of a forum selection clause is one of contract interpretation,” John Wyeth & Bro. Ltd. v. CIGNA Int&#x²⁷;l Corp., 119 F. 3d 1070, 1073 (3d Cir. 1997) (Alito, J.), and that "state law governs issues of contract interpretation,” AFC Franchising, LLC v. Purugganan,⁴³ F. 4th 1285, 1290 (11th Cir. 2022), we hold that courts must interpret a contract&#x²⁷;s forum-selection clause just like any other provision—under the substantive law governing the contract. In doing so, we join the "growing trend” among federal courts to recognize "that there are two separate steps to analyzing a forum-selection clause: (1) applicability based on state law (and/or the law of the contract), and (2) enforceability based on federal common law.” Firexo, 99 F. 4th at 322–23.

Applying this rule, we find that Slovenian law—which does not recognize non-signatories&#x²⁷; ability to invoke contractual provisions via equitable estoppel—governs the Declan and RRA Contracts forum-selection clauses. Since the non-signatory Defendants cannot invoke those clauses, there is no “valid forum-selection clause" applicable to the Plaintiffs&#x²⁷; claims, meaning the district court had no reason to apply Atlantic Marine&#x²⁷;s modified forum non conveniens test. Therefore, because the district court applied the wrong legal standard, it necessarily abused its discretion in dismissing Counts I and II for forum non conveniens.

Our analysis proceeds in five steps. First, we explain how issues implicating a forum-selection clause&#x²⁷;s "applicability" are distinct from, and antecedent to, issues of its “enforceability.” Second, we conduct an Erie² analysis to establish that defining the applicability of a forum-selection clause poses a substantive issue that cannot be governed by federal common law. Third, applying Florida&#x²⁷;s choice-of-law rules, we find that the Declan and RRA Contracts, including their forum-selection clauses, are governed by Slovenian law. Fourth, we consider the parties&#x²⁷; submissions on Slovenian law and determine that Slovenian law does not allow the non-signatory Defendants to invoke the forum-selection clauses. Finally, having found that the forum-selections clauses are not applicable in this case, we conclude that the district court erred by relying on Atlantic Marine to exclude the relevant private-interest factors from its forum non conveniens analysis. We take each step in turn.

1.

We have long recognized that the “enforceability of forumselection clauses is governed by federal law." AQuate, 100 F. 4th at 1323 (first citing P&S Bus. Machs., 331 F. 3d at 807; then citing Great Lakes Ins. SE v. Raiders Retreat Realty Co., 601 U.S. 65, 71–72 (2024)); accord Stewart Org., Inc. v. Ricoh Corp., 810 F. 2d 1066, 1067 (11th Cir. 1987) (en banc), aff&#x²⁷;d and remanded, 487 U.S.²² (1988). But, as the Plaintiffs see it, this case is not about the enforceability of forumselection clauses but rather their threshold applicability to the

2 Erie R. Co. v. Tompkins, 304 U.S. 64, 71 (1938).

claims presented here. Before proceeding any further then, we must define our terms and determine the extent to which these concepts are analytically distinct.

Courts have not always spoken with precision when analyzing forum-selection clauses. See Matthew J. Sorensen, Note, Enforcement of Forum-Selection Clauses in Federal Court after Atlantic Marine, 82 Fordham L. Rev. 2521, 2546–47 & n.227 (2014); see also Barnett v. DynCorp Int&#x²⁷;l, L.L.C., 831 F. 3d 296, 302 (5th Cir. 2015) (“"[W]e do not appear to have drawn his distinction between validity and enforceability, instead seeming to treat those words as synonyms in the forum-selection clause context.”). As we recently observed, "[o]ur cases have inconsistently used the terms &#x²⁷;valid&#x²⁷; and &#x²⁷;enforceable&#x²⁷;... without explaining whether, or how, these terms differ." AQuate, 100 F. 4th at 1323 n.4 (first citing Krenkel v. Kerzner Int&#x²⁷;l Hotels Ltd., 579 F. 3d 1279, 1281 (11th Cir. 2009); then citing Turner v. Costa Crociere S.p.A.,⁹ F. 4th 1341, 1345 (11th Cir. 2021)).

In general, we have referred to a forum-selection clause&#x²⁷;s "enforceability" or "validity” when "articulating the effect" of the test announced in M/S Bremen v. Zapata Off-Shore Co. (The Bremen), 407 U.S. 1 (1972), on forum-selection clauses. AQuate, 100 F. 4th at 1323 n.4. In The Bremen, the Supreme Court explained that a court should “enforce [a] forum clause specifically unless [the plaintiff] could clearly show that enforcement would be unreasonable and unjust, or that the clause was invalid for such reasons as fraud or overreaching." 407 U.S. at 15 (emphases added). To answer those questions, we have looked to federal common law, and will

"invalidate”—that is, refuse to enforce—a forum-selection clause if "(1) its formation was induced by fraud or overreaching; (2) the plaintiff would be deprived of its day in court because of inconvenience or unfairness; (3) the chosen law would deprive the plaintiff of a remedy; or (4) enforcement of the clause would contravene public policy." AQuate, 100 F. 4th at 1322 (quoting Krenkel, 579 F. 3d at 1281). Although both “enforceability" and "validity” are included in The Bremen test, it appears that these concepts may describe different characteristics of a forum-selection clause: The Bremen test frames each concept as turning on different circumstances, conditioning the former on whether giving effect to the clause would be "unreasonable and unjust,” and the latter on whether the clause was the product of "fraud or overreaching.” The Bremen, 407 U.S. at 15.

It is sufficient for present purposes to simply recognize that “enforceability” and “validity" are analyzed within The Bremen&#x²⁷;s framework for deciding the extent to which a court will bind the contracting parties to their bargained-for language or otherwise ignore a forum-selection clause on fairness, contract-formation, or public-policy grounds. See AQuate, 100 F. 4th at 1323. That is because "the effect of The Bremen&#x²⁷;s test on forum-selection clauses” is not at issue in this appeal. See id. at 1323 n.4. The Plaintiffs do not ask us to nullify the forum-selection clauses in the Declan and RRA Contracts, and do not argue that those clauses are themselves the products or sources of any unfairness between the parties to them. Rather, they ask us to determine exactly who those clauses can be enforced by and against in the first place—i.e., to whom they apply.

Our Circuit has not yet determined whether questions of a forumselection clause&#x²⁷;s "applicability" or "scope," such as the extent to which the clause can bind a non-signatory party, are “distinct from and antecedent to [questions of] its enforceability.” Firexo, 99 F. 4th at 319 (emphasis omitted). We now hold that they are.

Before a court can assess whether the parties to a lawsuit should be bound by a forum-selection clause&#x²⁷;s terms, it must first know the extent to which the clause applies to the parties&#x²⁷; claims at all. See, e.g., Slater v. Energy Servs. Grp. Int&#x²⁷;l, Inc., 634 F. 3d 1326, 1330–31 (11th Cir. 2011) (considering whether claims “fit within the scope of the . forum-selection clause" before determining clause&#x²⁷;s enforceability); 14D Chas. A. Wright & A.R. Miller, Federal Practice and Procedure § 3803.1 (4th ed. 2025) (distinguishing between issues of whether the “agreement [is] enforceable” and whether "the clause appl[ies] to the dispute at hand"). Delineating the scope of a forum-selection clause requires the court to assess whether the clause is “mandatory” or “permissive,” see Snapper, Inc. v. Redan, 171 F. 3d 1249, 1262 n.24 (11th Cir. 1999), whether it covers the causes of actions plead, see Slater, 634 F. 3d at 1330–31, and whether it extends to the parties at bar, see Usme v. CMI Leisure Mgmt., Inc., 106 F. 4th 1079, 1087 (11th Cir. 2024). None of The Bremen factors we consider in analyzing a forum-selection clause&#x²⁷;s “enforceability" or "validity" provide any guidance for answering these questions. Cf. AQuate, 100 F. 4th at 1322.

Instead, we can only determine a forum-selection clause&#x²⁷;s "scope" by looking to the language of the contract itself. Slater,

634 F. 3d at 1330. This preliminary question of "[w]hether and how a [forum-selection] provision applies to the parties or claims in a lawsuit" thus presents a matter of “interpretation[,] . . . analytically distinct... from the enforceability of that clause.” Firexo, 99 F. 4th at 310, 324 (quoting In re McGraw-Hill Global Edu. Holdings LLC, 909 F. 3d 48, 58 (3d Cir. 2018)); see Weber, 811 F. 3d at 770–71; Martinez, 740 F. 3d at 217-18; Yavuz, 465 F. 3d at 430. Accordingly, when tasked with analyzing a forum-selection clause, a court must follow a twostep approach: (1) the court first must interpret the clause to assess whether its terms apply to the claims and parties at bar; if they do, then (2) the court must decide whether the forum-selection clause is valid and enforceable based on The Bremen factors. Our precedent dictates that the enforceability of a forum-selection clause is a procedural matter governed by federal common law. ³ See Stewart, 810 F. 2d at 1068. We next consider whether the same is true for the issue of applicability as well.

2. Identifying the appropriate body of law that a federal court exercising diversity jurisdiction must apply in interpreting a forum-

3 Picking up on the conceptual distinction between “enforceability” and “validity," some courts have identified the possibility that validity issues implicating the formation of a forum-selection clause should be resolved based on state contract law rather than federal common law. See Barnett, 831 F. 3d at 301–03; Nw. Nat&#x²⁷;l Ins. Co. v. Donovan, 916 F. 2d 372, 374 (7th Cir. 1990). Because the parties do not challenge the validity of the forum-selection clauses, we need not weigh in on that issue today.

selection clause poses an issue of first impression for our Court.⁴ Under Erie&#x²⁷;s longstanding command, a federal court sitting in diversity must "apply state substantive law and federal procedural law," see Garcia v. Chiquita Brands Int&#x²⁷;l, Inc., 48 F. 4th 1202, 1210 (11th Cir. 2022) (quoting Gasperini v. Ctr. for Humans., Inc., 518 U.S. 415, 427 (1996)); accord Erie, 304 U.S. at 71.⁵

In our Circuit, it is “well settled” that issues of contract interpretation are substantive matters governed by state law. AFC Franchising,⁴³ F. 4th at 1290 (citing Fernandez v. Bankers Nat&#x²⁷;l Life Ins., 906 F. 2d 559, 564 (11th Cir. 1990)). And determining the applicability of a forum-selection clause is simply an exercise in interpretation. See Slater, 634 F. 3d at 1330; John Wyeth & Bro., 119 F. 3d at 1073. Accordingly, our sister Circuits that have recognized the applicability-enforceability distinction uniformly apply the substantive law governing the contract to interpret a forum selection

4 The Defendants assert that the "great weight of intra-circuit law" dictates that we apply federal common law when interpreting forum-selection clauses. But we have never spoken directly on this issue. Rather our cases addressing the applicability of forum-selection clauses either (1) assumed without deciding that federal law governs this question, see Byers, 701 F. 3d at 1341; Usme, 106 F. 4th at 1087; Ocwen Orlando Holdings Corp. v. Harv. Prop. Tr., LLC, 526 F. 3d 1379, 1381 (11th Cir. 2008); accord Snapper, Inc. v. Redan, 171 F. 3d 1249, 1262 & n.25 (11th Cir. 1999) (applying “ordinary contract principles” but declining to "address the question of which jurisdiction&#x²⁷;s law to apply”), (2) held only that the "enforceability” of a forum-selection clause is governed by federal-common law, see Stewart Org., 810 F. 2d at 1067; AQuate, 100 F. 4th at 1323, or (3) did not implicate our diversity jurisdiction, see Slater, 634 F. 3d at 1326. 5 Foreign countries "must be considered just like a &#x²⁷;state&#x²⁷; for Erie and choiceof-law purposes.” Garcia, 48 F. 4th at 1210.

clause&#x²⁷;s applicability. See Firexo, 99 F. 4th at 326; In re McGraw-Hill, 909 F. 3d at 58; Weber, 811 F. 3d at 770; Martinez, 740 F. 3d at 217; Yavuz, 465 F. 3d at 430. We believe that approach is sound.

Contract law—including the rules governing contract interpretation is quintessentially substantive for Erie purposes, and therefore primarily the realm of the states.” Martinez, 740 F. 3d at 221 (first citing Alland v. Consumers Credit Corp., 476 F. 2d 951, 954– 55 (2d Cir. 1973); then citing Avery v. Hughes, 661 F. 3d 690, 693–94 (1st Cir. 2011)). Under our Erie framework, federal courts must apply the substantive law of a state “unless affirmative ‘countervailing federal interests&#x²⁷; are at stake that warrant application of federal law." Garcia, 48 F. 4th at 1210 (quoting Gasperini, 518 U.S. at 432). We see no sufficiently pressing federal interests that justify departing from the standard “constitutional &#x²⁷;allocation of judicial power between state and federal systems established&#x²⁷; in Erie.” Martinez, 740 F. 3d at 221 (quoting Hanna v. Plumer, 380 U.S. 460, 474 (1965) (Harlan, J., concurring)); cf. Erie, 304 U.S. at 77 ("There is no federal general common law."). On the contrary, upholding "valid forumselection clauses, bargained for by the parties, protects their legitimate expectations and furthers vital interests of the justice system” in promoting efficiency and predictability in litigation. Stewart, 487 U.S. at 33 (Kennedy, J., concurring); cf. Martinez, 740 F. 3d at 220 ("Applying federal law to construe a forum selection clause could frustrate the contracting parties&#x²⁷; expectations by giving a forum selection clause a broader or narrower scope in a federal court than it was intended to have.") Thus, forum-selection clauses must be

interpreted like any other contractual provision: under the substantive law that governs the contract.

Resisting this conclusion, the Defendants assert that determining the applicability of the forum-selection clauses to the claims presented here "does not involve any interpretation," since it "requires no parsing of contractual language or textual analysis whatsoever." Not so. "Every application of a text to particular circumstances entails interpretation." A. Scalia & B.A. Garner, Reading Law: The Interpretation of Legal Texts 53 (2012) (emphasis added); see also H.T. Tiffany, Interpretation and Construction, in¹⁷ American and English Encyclopedia of Law 1, 2 (Garland & McGehee eds., 2d ed. 1900) (defining interpretation as "the ascertainment of the thought or meaning of the author of, or the parties to, a legal document, as expressed therein, according to the rules of language and subject to the rules of law”). For instance, we cannot know that a plaintiff&#x²⁷;s claims “fit within the scope of the forum-selection clause" without first looking to the words it comprises. Slater, 634 F. 3d at 1330. And we cannot give those words any legal effect until we discern the substantive law governing their interpretation. Cf. Martinez, 740 F. 3d at 220 (recognizing that "the same word or phrase could have a different meaning” depending on the applicable governing law).

Both the Supreme Court and our Circuit have held in the analogous context of arbitration agreements that the substantive rules guiding this interpretation must derive from “traditional principles of state law." Lawson v. Life of the S. Ins. Co., 648 F. 3d 1166,

1170–71 (11th Cir. 2011) (quoting Arthur Andersen LLP v. Carlisle, 556 U.S. 624, 631 (2009)); cf. Vimar Seguros y Reaseguros, S.A. v. M/V Sky Reefer, 515 U.S. 528, 534 (1995) ("[F]oreign arbitration clauses are but a subset of foreign forum selection clauses.” (citation omitted)). These principles, the Supreme Court has told us, include the substantive rules of “state contract law regarding the scope of agreements (including the question of who is bound by them)” that dictate whether a contract can “be enforced by or against nonparties to the contract,” such as the availability of “estoppel." Arthur Andersen, 556 U.S. at 630–31 (internal quotation omitted) (quoting²¹ R. Lord, Williston on Contracts § 57:19, at 183 (4th ed. 2001)). We have already recognized in dicta that this applies with equal force to forum-selection clauses, see Usme, 106 F. 4th at 1087, and reaffirm that rule as part of our holding today. Thus, whether the Defendants may rely on equitable estoppel to bring the Plaintiffs&#x²⁷; claims within the scope of the Declan and RRA Contracts&#x²⁷; forum-selection clauses necessarily turns on the substantive law governing our interpretation of the contract.

The applicability of a forum-selection clause—like that of any contractual provision—presents a substantive issue that falls within the province of state contract law. Erie dictates that we must look beyond federal law to determine whether the Defendants can invoke the Declan and RRA Contracts&#x²⁷; forum-selection clauses against the Plaintiffs.

The district court did not do that. Ignoring the doctrinal distinction between a forum-selection clause&#x²⁷;s applicability and its

enforceability—and the choice-of-law issue arising therefrom—the district court erroneously applied federal common law to allow the Defendants to invoke those clauses based on equitable estoppel. But a non-signatory&#x²⁷;s ability to rely on a contract&#x²⁷;s forum-selection clause turns on whether “the relevant state contract law allows him" to do so. Lawson, 648 F. 3d at 1171 (first quoting Arthur Andersen, 556 U.S. at 632; then citing Bd. of Trs. v. Citigroup Global Mkts., Inc., 622 F. 3d 1335, 1342–43 (11th Cir. 2010)). So, having concluded that federal common law does not govern the forum-selection clause&#x²⁷;s applicability, we now must identify, under Florida state law, which jurisdiction&#x²⁷;s does.