Foreign Priority

Foreign priority allows a US patent applicant to claim the effective filing date of an earlier-filed foreign patent application: STATUTORY BASIS: 35 U.S.C. § 119(a): an application filed in the US for the same invention as filed in a foreign country within 12 months of the foreign filing date may claim the benefit of the foreign filing date; PARIS CONVENTION: the 12-month foreign priority right flows from the Paris Convention for the Protection of Industrial Property (1883); any applicant who files in a Paris Convention member country can claim priority to that filing in any other Convention member; the US is a Paris Convention member; EFFECT: claiming priority to the foreign application gives the US application an effective filing date (EFD) equal to the foreign filing date for subject matter disclosed in the foreign application; prior art between the foreign filing date and the US filing date generally does not count against the US claims (for supported subject matter); EXAMPLE: Inventor files in Japan on January 1, 2024; Inventor files US application on December 31, 2024 (within 12 months); US application's effective filing date for supported subject matter = January 1, 2024 (Japanese priority date); prior art published between January 1 and December 31, 2024 does not count against US claims supported by the Japanese application; DESIGN PATENTS: the foreign priority window for design patents is 6 months (not 12 months) under § 119(a); PROVISIONAL vs. FOREIGN FILING: foreign priority under § 119(a) works similarly to provisional benefit under § 119(e) — both establish an earlier EFD; foreign priority is available for first filings in foreign countries; provisional benefit is for earlier US provisional applications.

Foreign priority is not automatic — specific procedural requirements must be met to validly claim priority: REQUIREMENTS TO PERFECT PRIORITY: (1) FILE WITHIN 12 MONTHS: the US application must be filed within 12 months of the first foreign filing date; for design patents: 6 months; (2) SAME INVENTION: the foreign application and US application must be for the same invention; (3) CLAIM PRIORITY IN THE APPLICATION: the US application must identify the foreign application in the application data sheet (ADS) and in the first paragraph of the specification; (4) FILE A CERTIFIED COPY: a certified copy of the foreign application must be filed with the USPTO — typically submitted within the earlier of (a) 16 months from the foreign priority date or (b) 4 months from the US filing date; (5) TRANSLATION (IF REQUIRED): if the foreign application is not in English, a translation of the certified copy must be submitted; FAILURE TO FILE CERTIFIED COPY: the priority claim can be accepted without the certified copy if the foreign application's content is retrievable through a recognized patent office digital library (e.g., WIPO DAS, JPO, EPO), provided the applicant authorizes retrieval; LATE FILING: an unintentionally late priority claim can sometimes be restored by petition (37 C.F.R. § 1.55(e)); however, restoration requires: (a) the delay was unintentional; (b) the petition is filed within 14 months of the foreign priority date; MULTIPLE FOREIGN PRIORITIES: a US application can claim priority to multiple foreign applications, provided each is filed within 12 months of the US filing date.

The foreign application must adequately support each claim that relies on the foreign priority date — the same written description standard that applies to domestic provisional benefit: PRIORITY REQUIRES SUPPORT: a US claim only receives the benefit of the foreign priority date for subject matter that is adequately disclosed in the foreign application; a claim covering subject matter NOT in the foreign application uses the US filing date (not the foreign priority date) as the EFD; WRITTEN DESCRIPTION / ENABLEMENT: the foreign priority document must satisfy § 112(a) (written description and enablement) for each claimed feature; this is the same standard as for US provisional benefit; IN RE GOSTELI (Fed. Cir. 1989): three-part test for priority benefit — (1) the foreign application must satisfy § 112(a); (2) the same invention; (3) must be filed within 12 months; PARTIAL PRIORITY: it is possible for some claims in a US application to receive foreign priority while other claims (covering subject matter not in the foreign application) have a later EFD equal to the US filing date; WHAT HAPPENS IF PRIORITY DOCUMENT DOESN'T SUPPORT ALL CLAIMS: the claims supported by the foreign document receive the foreign EFD (blocking prior art between foreign and US filing dates); the claims NOT supported receive only the US filing date as EFD; prior art published between the foreign filing date and the US filing date can now be used against the unsupported claims; DISCLOSURE vs. CLAIMS: the foreign application does not need to have claims — it just needs to disclose the subject matter adequately.

The AIA's first-inventor-to-file system and § 102 prior art rules interact specifically with foreign priority claims: PRIOR ART CUTOFF DATE: with a valid foreign priority claim, prior art under § 102(a)(1) is assessed from the EFFECTIVE FILING DATE (the foreign priority date), not the US filing date; art published after the foreign filing date and before the US filing date does NOT count against properly supported claims; THIRD-PARTY FILINGS BETWEEN PRIORITY DATE AND US FILING DATE: if a third party files a US patent application between the foreign priority date and the US application's filing date, that third-party application may still be prior art under § 102(a)(2) — but only if the third party filed BEFORE the foreign priority date; if the third party filed AFTER the foreign priority date, they cannot antedate the applicant's effective filing date; GRACE PERIOD INTERACTION: the AIA's § 102(b)(1) grace period protects inventor-derived disclosures within 1 year before the EFFECTIVE FILING DATE; for a foreign priority claim, the grace period is measured from the FOREIGN PRIORITY DATE; this can affect whether an inventor's own pre-filing disclosures are protected; FOREIGN PUBLISHED APPLICATION AS PRIOR ART: a foreign patent application published before the US EFD is itself prior art under § 102(a)(1) against the US application; this includes the applicant's own foreign application if published before the US filing (though § 102(b)(1)(A) may protect own-inventor disclosures within 12 months of the foreign filing date); WORLDWIDE NOVELTY: under AIA, any worldwide disclosure (publication, public use, on sale) before the EFD is prior art — consistent with using the foreign priority date as the EFD.

These are two distinct paths for obtaining US patent protection for foreign-originated inventions: FOREIGN PRIORITY (§ 119(a)): applicant files a REGULAR US patent application (§ 111(a) non-provisional) within 12 months of the foreign filing; the US application claims priority to the foreign application; the US application is examined as any regular application; applicant controls prosecution directly; NATIONAL STAGE ENTRY (§ 371) — PCT ROUTE: applicant files a Patent Cooperation Treaty (PCT) international application within 12 months of the foreign filing (or directly); after 30 months from the priority date, applicant enters the 'national stage' in each desired country (including the US); § 371 national stage entry = entering the US phase of a PCT application; WHEN EACH IS USED: § 119(a) DIRECT FILING is used when the applicant wants protection in only a few countries and wants to control US prosecution directly; PCT NATIONAL STAGE is used when the applicant wants protection in many countries (10+), wants to delay national phase costs, or wants the international search report and written opinion before deciding where to file; PRIORITY DATE EFFECT: both § 119(a) direct filing and PCT national stage provide the same prior art benefit — the foreign priority date is the EFD for supported subject matter; DEADLINE: § 119(a): 12 months from foreign filing; § 371 national stage: 30 months from earliest priority date (extendable in some countries); the extra 18 months in PCT is a major advantage for startup and budget-constrained applicants; PROSECUTION HISTORY ESTOPPEL: both routes create prosecution history that can be used against claims in infringement proceedings.