Page:Lamps Plus, Inc. v. Frank Varela.pdf/15

12 of arbitration and thus creates a scheme inconsistent with the FAA.” Concepcion, 563 U. S., at 344; see Epic Systems, 584 U. S., at ___–___ (slip op., at 8–9). The same reasoning applies here: The general contra proferentem rule cannot be applied to impose class arbitration in the absence of the parties’ consent.

Our opinion today is far from the watershed claims it to be. Rather, it is consistent with a long line of cases holding that the FAA provides the default rule for resolving certain ambiguities in arbitration agreements. For example, we have repeatedly held that ambiguities about the scope of an arbitration agreement must be resolved in favor of arbitration. See, e. g., Mitsubishi Motors Corp., 473 U. S., at 626; Moses H. Cone Memorial Hospital v. ''Mercury Constr. Corp.'', 460 U. S. 1, 24–25 (1983). In those cases, we did not seek to resolve the ambiguity by asking who drafted the agreement. Instead, we held that the FAA itself provided the rule. As in those cases, the FAA provides the default rule for resolving ambiguity here.

Courts may not infer from an ambiguous agreement that parties have consented to arbitrate on a classwide basis. The doctrine of contra proferentem cannot