Use in commerce means genuine trademark use in the ordinary course of trade in commerce that Congress can regulate. A transaction arranged solely to reserve trademark rights is not sufficient.

For goods, the mark must identify the goods through an acceptable placement or display, and the goods must be sold or transported in qualifying commerce. For services, the mark must be used or displayed in selling or advertising the services, and the services must actually be rendered in qualifying commerce.

Operating in more than one state is not always required. Activities within one state may qualify where they affect interstate, territorial or US foreign commerce. Whether a particular business or transaction qualifies depends on the facts.

A Section 1(a) application requires qualifying use at filing. A Section 1(b) application can be filed before use, but an acceptable allegation of use is required before registration. Section 44(e) and Madrid Section 66(a) applications may register without pre-registration specimens. After registration, US maintenance filings generally require use for every retained item unless qualifying excusable nonuse applies.