Does a sale need to be public to trigger the on-sale bar?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

No, a sale does not need to be public to trigger the on-sale bar under 35 U.S.C. 102(b). The MPEP clarifies this point:

Unlike questions of public use, there is no requirement that “on sale” activity be “public.” “Public” as used in pre-AIA 35 U.S.C. 102(b) modifies “use” only. “Public” does not modify “sale.” (MPEP 2133.03(b))

This interpretation is based on case law, specifically Hobbs v. United States. It’s important to note that even private or confidential sales can potentially bar patentability if they occur more than one year before the patent application filing date. This applies to both pre-AIA and AIA (America Invents Act) patent applications.