PCT Filing

The Patent Cooperation Treaty (PCT) is an international treaty (administered by the World Intellectual Property Organization — WIPO) that allows inventors and companies to file a single international patent application that preserves the right to seek patent protection in over 150 contracting states. Filing a PCT application does NOT result in an 'international patent' — there is no such thing; patents are granted on a national and regional basis. Instead, the PCT application: (1) establishes an international filing date that serves as the priority date in all designated PCT member countries; (2) triggers an international search report (ISR) and written opinion (WO-ISA) from one of the authorized international searching authorities (USPTO, EPO, JPO, KIPO, CNIPA, and others); (3) gives the applicant up to 30 months from the earliest priority date to enter national phase in each selected country, where domestic patent prosecution then takes place. STRATEGIC VALUE: PCT filing is cost-effective for applicants who are uncertain which countries they need patent protection in — they pay a single PCT filing fee and the national/regional phase fees only for the countries they ultimately select; the 30-month window gives the applicant time to assess commercial prospects in each market before committing to expensive national phase prosecution fees.

The PCT filing deadline is 12 months from the earliest priority date (the filing date of the first application in a Paris Convention country). This is the same 12-month Paris Convention priority window. TYPICAL WORKFLOW: (1) Day 0: file provisional patent application in the U.S. (establishes priority date); (2) Month 12: file PCT application claiming priority to the U.S. provisional; the PCT application must be filed within 12 months of the provisional to claim the provisional's priority date; (3) ~Month 16–18: WIPO publishes the PCT application and the international searching authority issues the International Search Report (ISR) and Written Opinion; (4) Month 30: NATIONAL PHASE DEADLINE — the applicant must enter national phase in each selected country/region by 30 months from the earliest priority date (some countries have 31-month deadlines for Chapter II demand); (5) Post-month 30: prosecution in each selected national office proceeds under local rules. CHAPTER II (OPTIONAL): The applicant may file a 'Demand for International Preliminary Examination' (IPEA) before month 22 to obtain a more detailed International Preliminary Report on Patentability (IPRP Chapter II) — this gives additional feedback before national phase entry and may influence prosecution strategies.

PCT filing involves multiple fee components: (1) INTERNATIONAL FILING FEE — paid to the receiving office and forwarded to WIPO; for applications filed with the USPTO as receiving office and searched by the USPTO: ~$1,900–$2,800 for large entity; $950–$1,400 for small entity; $285–$420 for micro entity (actual amounts depend on number of pages — baseline up to 30 pages; excess page fees apply); (2) SEARCH FEE — paid to the International Searching Authority (ISA); if the USPTO is the ISA: ~$2,100 large / $1,050 small / $315 micro entity; if the EPO is the ISA: different schedule; (3) TRANSMITTAL FEE — paid to the receiving office: ~$240 USPTO; (4) NATIONAL PHASE FEES — paid country by country when entering national phase (month 28–30); major market estimates for a single application: U.S. national phase: $1,000–$3,000 (plus attorney fees); European Patent Office (EPO): $1,500–$4,000 + national validation fees per country; China (CNIPA): ~$600–$1,200; Japan: ~$800–$1,500; South Korea: ~$500–$1,000; (5) ATTORNEY FEES — draft and file PCT: $3,000–$8,000 typically; respond to written opinion: $1,500–$3,000; each national phase entry adds attorney coordination costs. TOTAL COST ESTIMATE: PCT filing + major markets national phase (US, EP, CN, JP, KR) typically runs $25,000–$60,000+ over the full prosecution period.

The International Search Report (ISR) and Written Opinion (WO-ISA) are issued by the International Searching Authority (ISA) — typically 16–18 months after the PCT filing date: INTERNATIONAL SEARCH REPORT (ISR): a document listing prior art references (prior art patents, patent applications, and non-patent literature) that the ISA examiner found relevant to the claimed invention; prior art is classified as X (highly relevant — anticipates a claim), Y (relevant in combination with another document — suggests obviousness), A (background art), and other categories; the ISR identifies whether each listed document is relevant to novelty, inventive step, or both. WRITTEN OPINION (WO-ISA): a preliminary opinion from the ISA examiner assessing whether the claims appear to meet the requirements for patentability — novelty, inventive step (non-obviousness), and industrial applicability; indicates whether claims are likely allowable and, if not, why; the WO-ISA is not binding on national offices — it is advisory and may differ from national examination conclusions. STRATEGIC VALUE: the ISR and WO-ISA give the applicant early feedback on the strength of the patent application before committing to expensive national phase entry; if the WO-ISA raises serious prior art concerns, the applicant may: (1) amend the claims under PCT Article 34 to address the concerns before national phase; (2) decide not to enter national phase in some or all countries; (3) assess whether a continuation strategy is needed to improve claim scope.

At national phase entry (typically month 28–30 from priority date), the PCT application transforms into separate national applications in each selected country or regional patent system. The applicant must: (1) PAY NATIONAL FEES — each national office charges its own filing/entry fees; (2) FILE TRANSLATED DOCUMENTS — many countries require translation of the PCT application into the official language (e.g., Chinese, Japanese, Korean, Spanish for relevant offices); translation costs can be significant — $3,000–$10,000 per language for a typical application; (3) APPOINT LOCAL COUNSEL — most national offices require a locally registered patent attorney or agent; (4) PROVIDE NATIONAL PHASE SPECIFIC DOCUMENTS — assignment, sequence listings, declarations as required by each office; after entry, prosecution proceeds: EPO: one examination for coverage across 40+ European countries; single examination fee; validated separately in each country after grant; EPO grants typically cost $5,000–$15,000 in translation and validation fees across key European countries; CHINA: CNIPA prosecution takes 2–5 years typically; claims often need amendment for Chinese practice; JAPAN: JPO examination takes 2–4 years; request for examination required within 3 years; SOUTH KOREA: KIPO prosecution typically 2–3 years; streamlined by Korea's patent office efficiency record. In the U.S., if the applicant already has a U.S. application (the provisional or a U.S. nonprovisional) the PCT can enter U.S. national phase to continue prosecution in the U.S., or the applicant may rely on the earlier U.S. application.