COX, Circuit Judge:

Plaintiffs-Appellants (the Buyers) each sought to own a piece of paradise. To that end, they purchased undeveloped lots in a planned resort in the Bahamas. Their purchase contracts contain a provision that requires all disputes to be litigated in the Bahamas. Many of the Buyers financed their purchases with mortgage loans made by Bahamas Sales Associate, LLC (Bahamas Sales), a mortgage lender.

Apparently the real estate market tanked sometime after the Buyers purchased their lots. And in May 2010, the Buyers (who had received mortgage financing to purchase the lots) sued Bahamas Sales and others associated with Bahamas Sales, alleging that they engaged in appraisal fraud. Additionally, all of the Buyers sued various Ginn entities and Lubert-Adler Management Company entities, alleging fraud related to a loan transaction that had a negative impact on the planned resort.

The Defendants-Appellees moved to dismiss the Buyers' complaint for improper venue, alleging that, under the purchase contracts, venue is proper only in the Bahamas. The district court held that the complaint falls within the scope of the forum-selection clause in the purchase contract. The court then applied the doctrine of equitable estoppel to allow the Defendants-Appellees (all of which are nonsignatories to the contract containing the Bahamian forum-selection clause) to invoke the clause. The Buyers appeal the dismissal. We reverse and remand.

I. Facts and Procedural History1

The Buyers2 purchased lots in the Ginn Sur Mer subdivision on Grand Bahama Island in the Bahamas from Ginn-LA West End Limited (Ginn-LA). The marketing materials promoting Ginn Sur Mer promised many amenities, including a twenty-story grand palace, two signature golf courses, and a mega-yacht marina. Each Buyer entered into a purchase contract with Ginn-LA.3 Each contract contains a forum-selection clause and a choice-of-law clause that requires all disputes to be litigated in the Bahamas under Bahamian law. Specifically, each forum-selection clause provides:

(See, e.g., R.1-8 Ex. A ¶ 22.) Each choice-of-law provision states: "The local laws of the Commonwealth, without regard to the Commonwealth's choice of law rules, will exclusively govern the interpretation, application, enforcement, performance of, and any other matter related to, this Contract." (Id.) Only the Buyers and Ginn-LA (the seller) signed the lot purchase contracts.

Many of the Buyers applied for and received mortgage financing from Bahamas Sales.4 The mortgage notes also contain forum-selection clauses and choice-of-law clauses that each require disputes to be litigated in Florida under Florida law. The relevant clauses state:

(See, e.g., R.3-31 Ex. A ¶ 11.) Only the Buyers and Bahamas Sales are parties to the mortgage notes.

In May 2010, the Buyers who received financing from Bahamas Sales sued Bahamas Sales, Ginn Financial Services (the parent company of Bahamas Sales), Edward R. Ginn, III (an officer of Bahamas Sales), William McCracken (an officer of Ginn Financial Services)5, and Ginn Title Services (together, the Mortgage Entities), alleging that the Mortgage Entities participated in a scheme to produce fraudulent lot appraisals in violation of the Racketeer Influenced and Corrupt Organizations Act (RICO), 18 U.S.C. §§ 1961-1968. Specifically, the Buyers allege that the Mortgage Entities violated § 1962(c) and § 1962(d). The complaint seeks rescission of the notes and mortgages and restitution of payments made on the notes.

The appraisal-fraud claims allege that the Mortgage Entities fraudulently inflated the appraisals of their lots and used the inflated appraisals to set the amounts on the mortgage notes. Because of the inflated appraisals, the Buyers allege that they closed on the mortgage notes for amounts that far exceeded the market value of the lots. The appraisal-fraud claims assume that if proper appraisals had been done and the lots appraised for amounts lower than their sales prices, the Buyers would not have closed on the lots. Further, if proper appraisals had been done and the lots appraised for values less than their purchase prices, the Buyers claim that they could have simply walked away from the lot purchase contracts and paid only liquidated damages for their failure to close.

All of the Buyers also brought claims against other Ginn entities and Lubert-Adler Management Company entities (together, the Credit Suisse Entities)6 alleging fraud related to a loan transaction (the Credit Suisse fraud). The Buyers allege that the Credit Suisse Entities violated RICO § 1962(c) and § 1962(d).

The Buyers' Credit Suisse fraud claims allege that before the Buyers signed the lot purchase contracts, the Credit Suisse Entities entered into an arrangement to obtain a $675 million loan from Credit Suisse, a financial-services company. The $675 million loan was secured by various ownership interests in the parent company of Ginn-LA (the Ginn Sur Mer developer) and the land from five Ginn resort communities, including the Ginn Sur Mer subdivision. The repayment schedule on the loan required that all of the cash flow produced by the five Ginn resort communities be used to pay the Credit Suisse loan. As a result, Ginn-LA could not complete the marketed, but not contractually required, amenities. The Buyers further allege that if they had known about the Credit Suisse loan, they would not have purchased the Ginn Sur Mer lots.

Rather than answering the Buyers' complaint, the Mortgage Entities and Credit Suisse Entities filed motions to dismiss asserting that venue is only proper in the Bahamas as specified under the forum-selection clauses in the lot purchase contracts. The district court agreed. The court held that the Buyers' claims fall within the scope of the lot purchase contracts' forum-selection clauses. It also held that the Mortgage Entities and Credit Suisse Entities, though not signatories to the lot purchase contracts, could nevertheless enforce the forum-selection clauses under the doctrine of equitable estoppel. We reverse and remand.

II. Standards of Review

The enforceability of a forum-selection clause is a question of law that we review de novo. Slater v. Energy Servs. Grp. Int'l, Inc., 634 F.3d 1326, 1329-30 (11th Cir.2011). Further, whether the doctrine of equitable estoppel should apply is a question of law that we review de novo. Sunkist Soft Drinks, Inc. v. Sunkist Growers, Inc., 10 F.3d 753, 757 (11th Cir.1993).

III. Discussion

This appeal presents three issues: (A) whether Bahamas Sales agreed to venue in Florida under the mortgage notes; (B) whether the Buyers' appraisal-fraud claims and Credit Suisse fraud claims fall within the scope of the lot purchase contracts' forum-selection clauses; and (C) whether the Mortgage Entities and Credit Suisse Entities, as nonsignatories to the lot purchase contracts, can invoke the lot purchase contracts' forum-selection clauses. We address each issue in turn.

A.

The Buyers argue that the mortgage notes' forum-selection clauses bind Bahamas Sales as a party to the notes. This argument is foreclosed by our recent decision in Bahamas Sales Assoc., LLC v. Byers, 701 F.3d 1335 (11th Cir.2012). In Byers, we held that the mortgage notes only bind obligors under the notes, and Bahamas Sales is not an obligor because it is the party to which an obligation is owed.

B.

The Buyers next argue that their appraisal-fraud claims and Credit Suisse fraud claims do not fall within the scope of the lot purchase contracts' forum-selection clauses.7 We look to the nature of each of the Buyers' claims to determine if the claim falls within the scope of the lot purchase contracts' forum-selection clauses. Becker v. Davis, 491 F.3d 1292, 1300 (11th Cir.2007).

Both the Mortgage Entities and the Credit Suisse Entities contend that the Buyers' claims fall within the scope of the lot purchase contracts' forum-selection clauses. Our decision in Byers, however, forecloses the Mortgage Entities' argument. We held in Byers that the appraisal-fraud claims (identical to the appraisal-fraud claims in this case) do not fall within the scope of the forum-selection clauses. As a result, we need only address whether the Credit Suisse fraud claims fall within the scope of the clauses.

The purchase contracts' forum-selection clauses state, in relevant part, that:

(See, e.g., R.1-8 Ex. A ¶ 22.) We must determine whether the Credit Suisse claims are "related in any way" to the lot purchase contracts or any other agreements executed in connection with the lot purchase contracts.

A claim "relates to" a contract when "the dispute occurs as a fairly direct result of the performance of contractual duties." Telecom Italia, SpA v. Wholesale Telecom Corp., 248 F.3d 1109, 1116 (11th Cir.2001). Moreover, the fact that a dispute could not have arisen but for an agreement does not mean that the dispute necessarily "relates to" that agreement. Int'l Underwriters AG v. Triple I: Int'l Invs., Inc., 533 F.3d 1342, 1347 (11th Cir. 2008). The phrase "`related to' marks a boundary indicating some direct relationship." Doe v. Princess Cruise Lines, Ltd., 657 F.3d 1204, 1218 (11th Cir.2011). Requiring a direct relationship between the claim and the contract is necessary because, "[i]f `relate to' were taken to extend to the furthest stretch of its indeterminacy, it would have no limiting purpose because really, universally, relations stop nowhere." Id. at 1218-19 (quoting N.Y. State Conference of Blue Cross & Blue Shield Plans v. Travelers Ins. Co., 514 U.S. 645, 655, 115 S.Ct. 1671, 1677, 131 L.Ed.2d 695 (1995)) (internal quotation marks omitted).

In this case, the district court concluded that the Credit Suisse claims fall within the scope of the lot purchase contracts' forum-selection clauses because (1) the Buyers' claims arise out of a relationship that was established by the lot purchase contracts, (2) the Buyers would not have any claims had they not entered into the lot purchase contracts, and (3) the Buyers' claims are similar to the claims in Liles v. Ginn-La West End, Ltd., where we held that the claims fell within the scope of the lot purchase contracts' forum-selection clauses, 631 F.3d 1242 (11th Cir.2011).

For the Credit Suisse claims to fall within the scope of the purchase contracts' forum-selection clauses, the claims must have a direct relationship to the lot purchase contracts. They do not. The dispute between the Buyers and the Credit Suisse Entities is not a "fairly direct result of the performance of contractual duties" under the lot purchase contracts. See Telecom Italia, 248 F.3d at 1116. The Buyers do not allege that the Credit Suisse Entities interfered with Ginn-LA's performance obligations under the lot purchase contracts.

Moreover, the lot purchase contracts did not create the relationships between the parties. The only parties to the lot purchase contracts are the Buyers and Ginn-LA. The Buyers do not have a contractual relationship with any of the Credit Suisse Entities. And although the claims would not exist but for the Buyers purchasing the Ginn Sur Mer lots, this but-for relationship does not mean that the claims relate to the lot purchase contracts. The claims must result from the performance of duties under the lot purchase contracts; the Credit Suisse claims do not. In fact, the Buyers would still be able to bring their Credit Suisse fraud claims even if Ginn-LA had performed all of its obligations under the lot purchase contracts.

Furthermore, although Liles involved the same lot purchase contracts at issue here, the Buyers' claims differ from the claims alleged in Liles. In Liles, the plaintiffs alleged that the defendants (including Ginn-LA) violated the Interstate Land Sales Full Disclosure Act and fraudulently failed to disclose information relating to the titles to the properties. 631 F.3d at 1243. These allegations directly related to the lot purchase contracts. The dispute in Liles occurred as a result of the defendants' alleged failure to perform various contractual duties, including the duty to adhere to the Interstate Land Sales Full Disclosure Act and the duty to provide marketable titles to the lots. The lot purchase contracts expressly incorporate both of those duties.8 Here, as explained above, the Credit Suisse claims do not relate to the performance of duties under the lot purchase contracts.

The Credit Suisse Entities contend that the Credit Suisse fraud claims fall within the scope of the lot purchase contracts' forum-selection clauses because (1) claims of fraudulent inducement necessarily relate to the allegedly fraudulently induced contracts and (2) the Credit Suisse claims relate to "instruments executed in connection" with the lot purchase contracts.9

First, we reject the Credit Suisse Entities' argument that the Buyers allege fraudulent inducement of the lot purchase contracts and therefore that the claims relate to the contract. While we agree that claims of fraudulent inducement can relate to allegedly fraudulently induced contracts, see Prima Paint Corp. v. Flood & Conklin Mfg. Co., 388 U.S. 395, 87 S.Ct. 1801, 18 L.Ed.2d 1270 (1967), the Buyers do not allege that the Credit Suisse Entities fraudulently induced them to enter into the lot purchase contracts. And actually, it would be a rather nonsensical claim for the Buyers to suggest that the Credit Suisse Entities — which they did not know existed until after they purchased their Ginn Sur Mer lots — fraudulently induced them to purchase the lots.

Second, the Credit Suisse Entities' argument that the Credit Suisse fraud claims fall within the scope of the forum-selection clauses because they are "related in any way to ... any other agreement or instrument executed in connection with [the lot purchase contracts]" does not persuade us. The Credit Suisse claims have nothing to do with the mortgage notes, and the Buyers do not allege that the Credit Suisse fraud affected the notes. Instead, they allege that the Credit Suisse Entities used the Credit Suisse loan to "loot" the Ginn Sur Mer subdivision and, as a result, made it impossible for Ginn-LA to complete the marketed amenities to the subdivision.10

Because the Credit Suisse fraud claims do not have a direct relationship with the lot purchase contracts, the district court erred in concluding that the Credit Suisse fraud claims fall within the scope of the lot purchase contracts' forum-selection clauses.

C.

Having concluded that the Buyers' appraisal-fraud and Credit Suisse fraud claims do not fall within the scope of the forum-selection clauses, we also address the Buyers' final argument. They argue that the district court incorrectly applied equitable estoppel to allow the Mortgage Entities and the Credit Suisse Entities to invoke the lot purchase contracts' forum-selection clauses. The Buyers assert that their appraisal-fraud claims and Credit Suisse fraud claims do not rely on the lot purchase contracts and that, for this reason, the doctrine of equitable estoppel cannot properly be applied.

We hold in this case, as we held in Byers, that the district court erred in allowing the Mortgage Entities to invoke the lot purchase contracts' forum-selection clauses under the doctrine of equitable estoppel. The Buyers' appraisal-fraud claims do not allege concerted misconduct between the Mortgage Entities and Ginn-LA. Nor do the claims rely on the lot purchase contracts.

We write only to address whether the district court erred in applying equitable estoppel to allow the Credit Suisse Entities to enforce the forum-selection clauses.

First, we note that the parties litigated this case on the assumption that federal common law applies to the question of whether equitable estoppel should apply.11 All of the parties briefed and argued this case under federal common law as to the equitable estoppel issue. Therefore, we assume that federal common law applies in this case. See Chase Manhattan Bank v. Rood, 698 F.2d 435, 436 n. 1 (11th Cir. 1983) (assuming Florida law is the applicable substantive law in the case because both parties briefed and argued Florida law on appeal).

Generally, "one who is not a party to an agreement cannot enforce its terms against one who is a party." Lawson v. Life of the S. Ins. Co., 648 F.3d 1166, 1167 (11th Cir.2011). There are, however, exceptions to this rule. And the doctrine of equitable estoppel is one of them.

Equitable estoppel allows a nonsignatory to enforce the provisions of a contract against a signatory in two circumstances: (1) when the signatory to the contract relies on the terms of the contract to assert his or her claims against the nonsignatory and (2) when the signatory raises allegations of interdependent and concerted misconduct by both the nonsignatory and one or more of the signatories to the contract. MS Dealer Serv. Corp. v. Franklin, 177 F.3d 942, 947 (11th Cir. 1999). In essence, equitable estoppel precludes a party from claiming the benefits of some of the provisions of a contract while simultaneously attempting to avoid the burdens that some other provisions of the contract impose. Blinco v. Green Tree Servicing LLC, 400 F.3d 1308, 1312 (11th Cir.2005). A forum-selection clause would be one such burden.

The doctrine of equitable estoppel is grounded in fairness. As we noted in In re Humana Inc. Managed Care Litigation:

285 F.3d 971, 976 (11th Cir.2002) (citations omitted) (internal quotation marks omitted), rev'd on other grounds sub nom. PacifiCare Health Sys., Inc. v. Book, 538 U.S. 401, 123 S.Ct. 1531, 155 L.Ed.2d 578 (2003).

The Buyers' complaint does not allege concerted misconduct between the Credit Suisse Entities and Ginn-LA (the developer and signatory to the lot purchase contracts). Nevertheless, the Credit Suisse Entities argue that the concerted-misconduct circumstance applies here because the Credit Suisse fraud claims depend on conduct between the Credit Suisse Entities and Ginn-LA. That is, the Credit Suisse Entities assert that Ginn-LA's sale of the Ginn Sur Mer lots was a "necessary component" of the Credit Suisse scheme. According to the Credit Suisse Entities, the fact that Ginn-LA entered into lot purchase contracts with the Buyers "is fundamental to and inextricably connected with" the Credit Suisse Entities' conduct in the Credit Suisse fraud.

We have noted, however, that the application of equitable estoppel is appropriate when the signatory "raises allegations of substantially interdependent and concerted misconduct by both the nonsignatory and one or more of the signatories to the contract." MS Dealer, 177 F.3d at 947. The Buyers neither allege concerted misconduct between the Credit Suisse Entities and Ginn-LA in their complaint nor name Ginn-LA as a party to this action.12 Thus, the Credit Suisse Entities must look only to the first circumstance in which the doctrine of equitable estoppel applies. We therefore limit our inquiry to that circumstance — whether the Buyers rely on the terms of the lot purchase contracts in asserting their Credit Suisse fraud claims.

A party relies on the terms of a contract when the party needs the underlying contract to make out his or her claim against the nonsignatory. In re Humana, 285 F.3d at 976. The signatory must attempt to hold the nonsignatory to the terms of the contract. Becker, 491 F.3d at 1300.

A but-for relationship between the claims and the contract "alone is not enough to warrant equitable estoppel." Lawson, 648 F.3d at 1174. For a party's claims to rely on a contract, the party must actually depend on the underlying contract to assert the claims. In re Humana, 285 F.3d at 976. A simple but-for relationship does not constitute the actual dependence on the underlying contract that equitable estoppel requires. Scant authority exists that deals with this precise issue. Our view, however, comports with the view of two of our sister circuits. See Lenox MacLaren Surgical Corp. v. Medtronic, Inc., 449 Fed.Appx. 704, 709 (10th Cir.2011) (per curiam) ("For a plaintiff's claims to rely on the contract containing the arbitration provision, the contract must form the legal basis of those claims; it is not enough that the contract is factually significant to the plaintiff's claims or has a `but-for' relationship with them."); Brantley v. Republic Mortg. Ins. Co., 424 F.3d 392, 396 (4th Cir.2005) ("The district court correctly found that the mere existence of a loan transaction requiring plaintiffs to obtain mortgage insurance cannot be the basis for finding their federal statutory claims ... to be intertwined with that contract."). And the parties cite no precedent to the contrary.

Because the application of equitable estoppel is not a "rigid test, and each case turns on its facts," In re Humana, 285 F.3d at 976, we now turn to the facts of this case.

The Buyers allege that the Credit Suisse Entities fraudulently concealed the $675 million dollar loan from them. They allege that the Credit Suisse Entities "looted" the Ginn Sur Mer subdivision when the Credit Suisse Entities entered into the Credit Suisse loan and used the Ginn Sur Mer subdivision as collateral. As a result of the scheme, they allege that Ginn-LA could not complete the marketed amenities. This loan and the allegedly fraudulent scheme took place before any of the Buyers purchased their lots.

The Credit Suisse Entities argue that the Credit Suisse claims rely on the lot purchase contracts because if the Buyers had not entered into the purchase contracts, they would not have suffered damages from the alleged fraud.13 As previously noted, however, a but-for relationship between the lot purchase contracts and the claims is not enough to warrant the application of equitable estoppel.

The Credit Suisse Entities further contend that Liles forecloses the Buyers' argument that the claims do not rely on the lot purchase contracts. 631 F.3d at 1243. But Liles is distinguishable. As we said in Byers, the plaintiffs in Liles relied on the lot purchase contracts to make out their claims and therefore the court correctly applied equitable estoppel to allow the nonsignatories to invoke the forum-selection clauses. Without the lot purchase contracts, the plaintiffs would have been unable to bring their claims.

Here, the Buyers' Credit Suisse fraud claims do not rely on the lot purchase contracts. The Buyers do not seek to hold the Credit Suisse Entities to the terms of the lot purchase contracts. The Buyers simply allege that they could not benefit from the marketed amenities (which are not required under the lot purchase contracts) because of the Credit Suisse fraud. Additionally, the Buyers do not rely on any terms of the lot purchase contracts to establish the liability of the Credit Suisse Entities. It would be rather puzzling to say that the Credit Suisse fraud claims rely on the lot purchase contracts when the alleged fraud occurred before any of the Buyers purchased their lots.

Because the Credit Suisse fraud claims do not rely on the lot purchase contracts, we hold that the district court erred in applying the doctrine of equitable estoppel to allow the Credit Suisse Entities to invoke the lot purchase contracts' forum-selection clauses.

IV. Conclusion14

For these reasons, we hold that the district court erred when it determined that the Buyers' claims fall within the scope of the lot purchase contracts' forum-selection clauses. We also hold that the court erred in applying equitable estoppel to allow the Mortgage Entities and the Credit Suisse Entities (nonsignatories to the lot purchase contracts) to invoke the lot purchase contracts' forum-selection clauses. Accordingly, we reverse the district court's judgment granting the motions to dismiss for improper venue and remand for proceedings consistent with this opinion.

REVERSED AND REMANDED.