35 USC 371 governs entry of a qualifying PCT international application into the U.S. national stage. The central deadline is generally thirty months from the priority date. USPTO guidance requires the basic national fee and the required copy of the international application within that period to avoid abandonment as to the United States. A PCT filing does not automatically complete national-stage entry. [1][2]
Verify the priority date and application copy
Do not count thirty months only from the international filing date if an earlier priority date controls. Confirm whether the International Bureau already communicated the required application copy or whether another exception applies. Keep evidence of transmission and receipt rather than assuming a document exists in the national file. [2]
The U.S. deadline and the requirements of other designated offices can differ. A filing in one country does not preserve every other national-stage deadline.
Distinguish the basic entry requirements from later completion
Section 371 identifies fees, the international application and required English translation, relevant amendments and translations, and the inventor’s oath or declaration. The implementing framework treats some omissions differently from the basic fee and copy. [1]
USPTO’s national-stage guidance explains that a translation or specified additional items may be accepted through a notice procedure and applicable fees when the core entry requirements were met. It also expressly warns that the basic national fee cannot simply be paid late with a surcharge after the thirty-month deadline. Do not treat every missing item as having the same cure. [2]
Make the translation complete
Check the specification, claims, drawings with text, and relevant amendment materials against the required translation. Inconsistent terminology can create examination problems even when the filing is timely. Identify which version of an amendment is being supplied and the language in which it was originally submitted. [1][2]
Check fees without relying on an old total
National-stage fees can depend on the application, search or examination circumstances, claim counts, size, and entity status. USPTO directs users to current fee information. Confirm each component and payment authorization rather than relying on a flat amount copied from another application. [2]
- Calendar the controlling thirty-month date.
- Verify the copy and basic fee were timely received.
- Track translations, declarations, and notices separately.
- Retain official submission and payment confirmations.
See earlier filing-date benefit requirements and patent revival procedures for related issues that may arise when the filing history is incomplete.
Primary sources
- 35 USC 371 – National Stage: Commencement
- USPTO MPEP1893: National Stage and Thirty-Month Requirements
Sources checked: October 31, 2026.