Patent Priority

Patent priority refers to the effective date that is used to determine what counts as prior art against a patent claim: FIRST-INVENTOR-TO-FILE: under AIA (effective March 16, 2013), the US uses a first-inventor-to-file system; the patent goes to the inventor who is first to file, not first to invent (the pre-AIA rule); EFFECTIVE FILING DATE (EFD): the EFD is the date actually used to assess whether prior art defeats novelty (§ 102) or non-obviousness (§ 103); for a claim in a patent application: the EFD is the earliest filing date to which the claim has a complete and valid priority chain; WHAT EFD CONTROLS: ALL disclosures before the EFD are potential prior art; disclosures after the EFD are generally not prior art (subject to § 102(b) exceptions); for competing applications claiming the same invention, the one with the earlier EFD prevails; PROVISIONAL APPLICATION PRIORITY: a provisional patent application (35 U.S.C. § 111(b)) establishes an EFD; the non-provisional claiming the provisional's priority gets the provisional's filing date as the EFD — but ONLY for subject matter supported by the provisional's specification; matter added to the non-provisional that is not in the provisional has a later EFD (the non-provisional's filing date); INTERNATIONAL PRIORITY: under the Paris Convention, an applicant who files in one country can claim that country's filing date as priority in other countries within 12 months (patents/utility models) or 6 months (design patents); US applications can claim foreign priority under 35 U.S.C. § 119(a); PCT applications preserve priority internationally: the PCT international filing date becomes the EFD for all national phase applications entered within 30/31 months.

Provisional applications are a critical tool for establishing an early EFD: HOW PROVISIONAL PRIORITY WORKS: file a provisional application before any public disclosure; the provisional establishes a filing date; within 12 months of the provisional: file a non-provisional US application AND/OR a PCT application; the non-provisional/PCT claims priority to the provisional; claims in the non-provisional get the provisional's filing date as their EFD IF the provisional provides written description support; WRITTEN DESCRIPTION REQUIREMENT: the provisional must have sufficient written description for each claimed invention element; the test: 'the provisional application must describe the subject matter of the claim in sufficient detail that one skilled in the art could conclude that the inventor had possession of the claimed invention as of the provisional filing date'; New Railhead Mfg. v. Vermeer Mfg. (Fed. Cir. 2002): claims not fully supported by the provisional get the non-provisional's filing date; WHAT HAPPENS AFTER 12 MONTHS: if no non-provisional or PCT is filed within 12 months of the provisional, the provisional expires; it cannot be revived; the invention is still disclosed in the provisional, but no US patent can be obtained claiming the provisional's priority; MULTIPLE PROVISIONALS: a non-provisional can claim priority to MULTIPLE provisionals (even if filed in different years); this allows additional disclosures to be added; all provisionals must be listed in the non-provisional priority claim; PROVISIONAL QUALITY: because the provisional must support the non-provisional's claims, quality matters; a thin provisional may not support broad claims; best practice: draft the provisional with the care of a non-provisional; FOREIGN PRIORITY: the 12-month Paris Convention period starts from the provisional filing date for foreign filings too; a US provisional establishes priority for foreign filings within 12 months.

Continuation applications allow inventors to claim additional inventions from a parent application while maintaining the parent's filing date: CONTINUATION APPLICATION (CON): contains claims directed to the same invention as the parent; claims must be supported by the parent's specification (no new matter); uses the same specification as the parent; gets the parent's filing date as EFD; must be filed while the parent is still PENDING (before the parent issues or is abandoned); CIP (CONTINUATION-IN-PART): adds new matter to the specification; new matter has the CIP's own filing date as EFD; claims supported only by the new matter get the later EFD; claims supported by the original parent specification get the parent's EFD; DIVISIONAL APPLICATION: filed in response to a restriction requirement; claims a separate invention from the parent; same specification as parent; same EFD as parent; PRIORITY CHAIN: a continuation can itself have continuations; chain: provisional → non-provisional (parent) → continuation → continuation; each must be filed before the prior application issues or abandons; the EFD for each claim in the chain is the earliest application that provides written description support; CRITICAL FILING TIMING: a continuation must be filed BEFORE the parent issues as a patent (or is abandoned); if the parent issues without a continuation on file, no continuation can be filed; 35 U.S.C. § 120 requires: 'filed before the patenting or abandonment of or termination of proceedings on the first application'; PROSECUTION TIMING: applicants may delay prosecution of the parent while the continuation is pending to maintain copendency; 'keeping the chain alive' allows continued filing of continuations; STRATEGIC VALUE: continuation strategies allow multiple patents from a single application family, covering different claim scope.

The Patent Cooperation Treaty (PCT) allows a single filing to establish priority for applications in many countries: PCT INTERNATIONAL FILING: an international application (PCT) filed with the USPTO as receiving office preserves patent rights in 150+ countries; the PCT international filing date becomes the EFD for all national phase applications entered from that PCT; filing deadline: 12 months after the priority document (provisional, foreign application) under Paris Convention; PRIORITY CLAIM IN PCT: the PCT application can claim priority to an earlier US provisional (within 12 months) or an earlier foreign application (within 12 months); the PCT international filing date itself also serves as a priority date for subsequently entered national phase applications; NATIONAL PHASE ENTRY: 30 months from the earliest priority date for most countries (US, EP, China, Japan, etc.); some countries require 31 months; the national phase application inherits the PCT filing date as its EFD; WRITTEN DESCRIPTION FOR PCT PRIORITY: each claim in a national phase application must be supported by the PCT specification for the PCT filing date to serve as the EFD; claims not supported by the PCT specification get the national phase entry date as their EFD; PCT INTERNATIONAL SEARCH AND EXAMINATION: the PCT provides a non-binding International Search Report (ISR) and Written Opinion (WO); some patent offices (EPO) give significant weight to the ISR in national examination; PRIORITY RESTORATION: if a PCT application is filed more than 12 months but within 14 months of the priority application, the applicant may request restoration of priority; the receiving office determines if the late filing was 'unintentional' (US standard) or 'due care' (many other countries); PCT PUBLICATION: the PCT application is published 18 months after the priority date; the publication is prior art as of the PCT filing date.

Priority claim errors can result in loss of rights, invalid patents, or claims receiving a later effective filing date than expected: ERROR 1 — FILING THE NON-PROVISIONAL TOO LATE: if a non-provisional is filed more than 12 months after the provisional, it cannot claim the provisional's priority; the non-provisional gets its own filing date; any disclosures in the 12-month period may be prior art; PREVENTION: track the 12-month deadline from the provisional filing date; do not miss it; ERROR 2 — INADEQUATE PROVISIONAL SPECIFICATION: the provisional is filed with an incomplete description; the non-provisional adds subject matter to fill the gaps; claims based on the added matter get the non-provisional's filing date; any pre-filing disclosures between the provisional and non-provisional dates may be prior art for those claims; PREVENTION: draft the provisional with the same care as the non-provisional; MPEP § 1825.01 and § 2163 address written description in provisional applications; ERROR 3 — MISSING CONTINUATION DEADLINE: the continuation is not filed before the parent issues; no continuation can be filed after the parent issues; PREVENTION: monitor parent application status; file continuation before allowance or at latest before issuance; ERROR 4 — FAILURE TO CLAIM PRIORITY IN THE PETITION: the priority claim must be expressly stated in the application's Application Data Sheet (ADS); a failure to claim priority in the ADS can be corrected but with procedural complexity; PREVENTION: confirm the ADS includes all intended priority claims at filing; ERROR 5 — PRIORITY CLAIM TO ABANDONED APPLICATION: claiming priority to an application that has been abandoned without a valid continuation chain; the abandoned application may not support priority; PREVENTION: verify the entire priority chain is intact when filing new continuations.