How is the ‘relevant date’ determined for prior art in international patent applications?

The ‘relevant date’ for determining prior art in international patent applications is defined in MPEP 1878.01(a) and PCT Rule 64.1(b). It is generally:

• The international filing date of the application
• The filing date of an earlier application if priority is claimed and valid
• In some cases, the filing date of an earlier application even if the international filing date is up to two months after the priority period expired

The MPEP states: “When a potentially relevant document has been published between a claimed priority date of the application and its international filing date, the examiner is required to consider whether the claimed priority date is valid for the purposes of determining the ‘relevant date’ of the claims in the international application.”

To learn more:

• relevant date
• prior art
• international patent application
• PCT
• priority date