The expansion-of-trade doctrine has limited application in ex parte proceedings, and the Trademark Trial and Appeal Board has indicated that "[i]t is not necessary, . . . in the context of an ex parte proceeding, for the Office to show that the owner of the particular registration that has been cited against the application has expanded or will expand its goods or services." In re 1st USA Realty Pros., Inc., 84 USPQ2d 1581, 1584 & n.4 (TTAB 2007) ; see also In re Kysela Pere et Fils, Ltd., 98 USPQ2d 1261, 1266 (TTAB 2011) .

The doctrine is typically applied in inter partes proceedings where an opposer claims that its priority of use of a mark with respect to its goods/services should be extended to include applicant’s goods/services because they are in the natural scope of expansion of opposer’s goods/services. See Orange Bang, Inc. v. Olé Mexican Foods, Inc., 116 USPQ2d 1102, 1119 (TTAB 2015) (noting that the "natural zone of expansion" doctrine normally applies in inter partes cases in the context of the parties’ dueling claims of priority); see also Dollar Fin. Grp., Inc. v. Brittex Fin., Inc., 132 F.4th 1363, 1370 (Fed. Cir. 2025) (explaining that, because "an earlier registration does not establish priority for a later application when the goods or services are different," the expansion-of-trade doctrine may only be used "to prevent junior users from registering similar marks on goods[/services] in a senior user’s zone of natural expansion," but not "to establish priority in different goods or services").

However, in the ex parte context, the normal relatedness analysis is applied:

[W]e look at the question of the relatedness of the services identified in applicant's application and those in the cited registration based on whether consumers are likely to believe that the services emanate from a single source, rather than whether the Examining Attorney has shown that the registrant . . . has or is likely to expand its particular business to include the services of applicant.

1st USA Realty Prof’ls, 84 USPQ2d at 1584.

To the extent the expansion-of-trade doctrine does apply in ex parte cases, it "is considered through a traditional relatedness of goods and services approach." Id. at 1584 n.4.