Guide · Filing abroad
There is no such thing as an international patent.
It's the most common misconception in all of IP. Patents are territorial — every country grants its own. What people call 'international patenting' is really a set of treaties that make it cheaper and slower to file in many countries at once. Here's how it actually works.
The one thing to understand
Patents are territorial.
A US patent stops infringementinfringementMaking, using, selling, or importing a patented invention without permission from the patent holder.Read more → in the United States — and nowhere else. If you want to stop a factory in Germany or a seller in Japan, you need a patent granted by Germany or Japan. There is no central authority that grants a single patent enforceable everywhere; the World Intellectual Property Organization administers treaties, but it does not grant world patents.
So 'going international' always means obtaining a bundle of separate national patents. The treaties below don't change that — they just give you cheaper, more coordinated ways to pursue the bundle, and more time to decide which countries are worth it.
Three ways to file abroad
Direct (Paris Convention)
Best for: 1–3 countries, decided early
File in your home country, then file directly in each other country within 12 months, claiming your original filing datefiling dateThe day the patent application was submitted to the USPTO. Sets the priority date for prior-art comparisons.Read more →. Simple and cheap if you only want a few markets — but you commit to the countries (and their translation + agent costs) at the 12-month mark.
PCT (Patent Cooperation Treaty)
Best for: Many countries, or undecided
One 'international application' filed with WIPO preserves your right to seek a patent in 150+ member states. It does not grant a global patent — it buys time. You get a search report on patentability and defer the expensive country-by-country filings to the 30-month mark.
Regional (EPO, etc.)
Best for: A whole region at once
Some regions grant through one office: the European Patent Office examines once, then you validate in chosen countries — or take the new Unitary Patent for single-effect coverage across participating EU states. Similar systems exist via ARIPO, OAPI, and the Eurasian patent office.
The PCT clock
What the 30-month timeline buys you
The PCT's real product is time. Instead of committing to every country at 12 months, you defer the big spend to 30 months — long enough to see traction, raise money, and read the search report before paying for translations and local agents.
Month 0
Priority filing
File your first application (often a US provisionalprovisionalA simplified, lower-cost patent application that locks in a filing date for 12 months while the inventor refines or pitches.Read more → or national application). This date is your priority datepriority dateThe earliest date used to compare the patent against prior art. Usually equals the filing date.Read more → — the clock everything else counts from.
By month 12
File the PCT application
File one international application with WIPO, claiming priority. This locks in your filing datefiling dateThe day the patent application was submitted to the USPTO. Sets the priority date for prior-art comparisons.Read more → across all 150+ PCT member states at once.
~Month 16
Search report + written opinion
An International Searching Authority issues a search report and a non-binding opinion on whether your invention looks novel and inventive — a cheap early read before you spend big.
Month 30
National / regional phase
The real decision point: enter the national phase only in the countries you actually want, paying each office's fees, translations, and local-agent costs. Skip a country and you have no rights there.
The trap that kills foreign rights
Most countries give you no grace period.
The US lets you file up to 12 months after your own public disclosure. Almost nowhere else does. Most countries require absolute noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → — disclose, sell, or demo your invention before filing and you may have permanently barred a patent there. If international protection matters, file before you go public, not after.
Costs add up fast, too: translations, national filing fees, and local agents mean broad international protection routinely runs into the tens or hundreds of thousands. Most applicants file only in their key markets — commonly the US, Europe, China, Japan, and Korea.
Next steps
Get the home-country basics right first.
International strategy starts with a solid first filing and a clear picture of what you're protecting. Sort that out before the 12-month Paris clock starts running.
This is a plain-English overview, not legal advice. International filing deadlines are strict and unforgiving — work with a patent attorney before relying on any of it. PatentBrief is not a law firm.