PCT vs Paris Convention: Which Route Should You Use for Foreign Filing?

The Common Starting Point

Both routes begin with a first filing, usually a US non-provisional or provisional application. Under the Paris Convention, that filing opens a twelve-month window in which later applications abroad can claim its date. Paris Convention priority is the foundation of both routes; the PCT simply adds a centralized step inside that window.

The twelve-month date is fixed. Whichever route is chosen, something must be filed by then, or foreign rights based on the original date are generally lost.

The Paris Route: Filing Directly

Under the direct route, the applicant files a separate national or regional application in each target office, such as the European Patent Office, the Japan Patent Office, or the China National Intellectual Property Administration, within twelve months of priority. For design applications, the period is six months.

Each application proceeds independently from the start. That brings three advantages:

• Speed: Examination begins sooner in each office, which can matter when a competitor's product is already on the market
• Lower total cost for few countries: There is no international filing fee layer when protection is needed in only one or two places
• Wider reach: Some jurisdictions are not PCT members, most notably Taiwan, and can only be reached directly

The drawback is that every translation, local agent, and national fee is due at twelve months, often before the applicant knows whether the product will succeed.

The PCT Route: One Filing, Deferred Decisions

A PCT application is a single international filing, made with a receiving office such as the USPTO, that designates all PCT contracting states. It does not produce an international patent. Instead, it preserves the right to enter the national phase in each chosen country later, generally thirty months from the earliest priority date, and thirty-one months at the EPO and several other offices.

Along the way, the applicant receives:

1. An international search report and written opinion on patentability, typically before the eighteen-month publication
2. International publication at eighteen months from priority
3. The option to file a Chapter II demand for international preliminary examination, which allows claim amendments and argument before national entry

The main benefit is time. The applicant gains about eighteen extra months to assess commercial value, licensing interest, and the search results before committing to national fees and translations.

Choosing Between Them

The PCT route usually makes sense when:

• Protection may be needed in more than a handful of countries
• The invention's commercial importance will be clearer in a year or two
• The search report will inform whether and where to proceed
• Budget for foreign filing is limited in the current year

The direct Paris route usually makes sense when:

• Only one or two foreign countries matter
• Early grant is important for enforcement or licensing
• A key market, such as Taiwan, is outside the PCT

Many applicants combine them: a PCT application for broad coverage plus a direct filing in Taiwan, or a direct filing in one priority market alongside a PCT application for the rest.

Costs to Plan For

Neither route is free of cost surprises. The PCT adds its own filing, search, and transmittal fees, which are wasted if only one country is eventually pursued. The direct route front-loads translation costs, which are often the largest single element of foreign filing. A realistic comparison models the total cost of each route across the likely country list, not just the fees due at twelve months.

Docketing the Decision Points

Each route creates its own chain of deadlines: the twelve-month foreign filing date, the Chapter II demand date, the thirty- and thirty-one-month national phase dates, and each national office's subsequent requirements. These belong in the docket as soon as the first application is filed. ArcPrime's global filing strategy tools model country lists and route costs for each family so the decision is made on data rather than habit.