PCT National Phase Entry vs Direct Filing in Korea: Key Differences

Securing patent protection abroad requires filing in each target country. There are two routes. Either file directly in each country within 12 months of the priority date (Paris route), or file a single PCT international application within 12 months and enter each designated office within 30 to 31 months. Korea uses the latter timeline: under Article 201 of the Korean Patent Act, the Korean translation must be submitted within 31 months from the priority date.

Both routes secure a filing date, but they differ in decision timing, translation cost, examination flow, and fee reductions. This guide covers both directions: Korean applicants going abroad via PCT, and foreign applicants entering Korea via PCT national phase.

Core Differences Between the Two Routes

Direct filing under the Paris Convention requires submitting both the application and the translation in each country's language within 12 months of the priority date. If you target five countries, you must complete five translations and appoint five local agents within 12 months. The PCT route lets you file once in Korean, English, or Japanese at the international stage, and defer entry into each designated country until 30 to 31 months from the priority date.

This 19-month difference is the main reason applicants choose PCT. For inventions with uncertain market value, you can review the International Search Report (ISR) issued around 18 months from the priority date before deciding which countries to enter. If patentability looks weak, you can simply skip national phase entry and save the associated costs.

The 31-Month Deadline at KIPO

The PCT itself sets 30 months as the default, but each contracting state may extend this in domestic law. Korea, the EPO, Australia, India, and Russia apply 31 months. The US, Japan, China, and Canada keep 30 months. The one-month gap looks small, but foreign headquarters that manage all jurisdictions on a uniform 30-month docket regularly miss Korea's 31 months. The reverse error is also common: a Korean applicant assuming 31 months across the board files into the US at month 31 and finds the application deemed withdrawn.

If the Korean translation is not filed by the deadline, the application is deemed withdrawn and recovery is severely limited in practice. Some smaller jurisdictions have additional rules: Luxembourg and Tanzania apply 30 months only when international preliminary examination is requested within 19 months of the priority date.

Korean Applicant Perspective

When a Korean applicant targets the US, Europe, China, and Japan, the PCT route saves both time and procedural overhead. At month 12, only one Korean PCT application needs to be ready. Per-country translation and local agent selection happen at month 30, after market validation. By that point, the ISR and written opinion are in hand, so claims with weak prospects can be amended or dropped before incurring per-country costs.

Korea filed 23,851 PCT applications in 2024, ranking fourth worldwide for the fifth consecutive year, with year-on-year growth of 7.1%. While the US, Japan, and Germany all declined, Korea was the only top-five origin to grow meaningfully. For Korean companies expanding internationally, PCT has effectively become the default rather than an option.

Foreign Applicant Perspective: Entering Korea

A foreign applicant entering Korea must submit a Korean translation and the entry document to KIPO within 31 months of the priority date. The description, claims, drawings (textual portions), and abstract must all be translated into Korean. Note that Korea recognizes English as the only foreign language for foreign-language applications.

Examination is not automatic; the request for examination and its fee must be filed within three years of the filing date. If KIPO authored the ISR or IPRP, the examination fee is reduced by 70%. EPO-authored ISR yields a 10% reduction. This sliding scale is one of the strongest reasons to use KIPO as the receiving and search office.

Translation and Cost Structure

PCT-route costs fall into three layers: international-stage PCT fees (around CHF 1,330), national-stage KIPO filing fees, and translation fees that span both stages. Translation is typically priced per word or per page on the Korean–English language pair and scales with specification length.

• International filing fee (IB): approx CHF 1,330, with up to CHF 300 reduction for electronic filing
• International search fee (KIPO as ISA): KRW 450,000
• Transmittal fee: KRW 45,000
• Korean national-stage filing fee: same scheme as a regular Korean application (KRW 46,000+ electronic, with per-claim surcharges)
• Examination fee: 70% reduction if KIPO authored the ISR or IPRP
• Translation fee: varies by length, language pair, turnaround (the largest variable in practice)

When Direct Filing Is Better

PCT is not always the right answer. If only one or two countries are targeted and immediate prosecution is needed, the PCT international fee is pure overhead. PCT also leaves examination to each designated office, which means double work compared with a single national process. Direct filing in turn lets you tailor claim scope to each examiner's prior art, which can yield broader rights in some jurisdictions.

1. When the target list is fixed at one or two countries: direct filing is cheaper
2. When fast grant matters more than scope flexibility: PCT can be a delay
3. When you want claim scope to differ by country: direct filing is more flexible
4. When the target list spans three or more countries or is not yet decided: PCT wins

Frequently Asked Questions

Q. Does a PCT application alone produce a granted patent?

No. A PCT application is not an "international patent." It only secures a uniform filing date in every designated office. Actual grant requires a separate national-phase examination in each office.

Q. Can I recover if I miss the 31-month deadline by one day?

Korea allows reinstatement only on narrow grounds. Routine docketing errors do not qualify. Treat the 31-month date as an absolute deadline. Remembering that the count starts from the priority date and that holidays roll forward to the next business day prevents most accidents.

Q. Is PCT international preliminary examination (IPRP) mandatory?

No. But a KIPO-authored IPRP unlocks the 70% examination-fee reduction in Korea and gives one extra round of claim amendment. If you intend to prosecute and Korea is a primary jurisdiction, the cost-benefit usually favors requesting it.

Q. What if a Korean applicant misses the 12-month PCT priority window?

You can still file PCT without claiming priority, but the PCT filing date becomes the priority date and the earlier Korean application can become prior art against you. If the earlier Korean application has not yet published, refiling as a fresh PCT may be considered, weighed against self-collision risk.