For U.S. startups developing innovative technology, the decision of where and how to file international patents requires a careful balance of strategic considerations versus costs. After filing your initial U.S. application, you have exactly 12 months under the Paris Convention to decide where else to seek protection—and this deadline is non-extendible. (A two-month “restoration” period sometimes is available if the 12-month deadline is missed.) Given the potentially high costs of pursuing non-US patent protection, startups must start thinking about where (and if) to file internationally long before the 12-month date.

The Global Patent Landscape

The numbers tell a compelling story about where innovation matters most. Five jurisdictions—the U.S., European Patent Office (EPO), Japan, South Korea, and China—account for 89% of global patent filings. For U.S. companies, the typical filing order after the domestic application is EPO, China, Japan, then Korea. This pattern reflects both market size and strategic importance for American businesses.

However, raw filing numbers don't tell the whole story. Your filing strategy should be driven by commercial realities, not just where everyone else is filing. Ask yourself: Where are your current and future markets? Where are your competitors based, and where do they manufacture? Where would enforcement actually matter for your business model? Does the judicial system of a particular country operate effectively so you can conceive of suing an infringer there, or is having a granted patent, as a deterrent on paper only, sufficient? The answers to these questions might lead you to file in smaller markets like Canada, Australia, Israel, or elsewhere.

Commercial Strategy Over Geography

Smart patent filing requires thinking like a business strategist, not just following geographical checklists. Consider the emerging markets that will matter in 5-10 years, not just today's revenue centers. If you're licensing technology, focus on where potential licensees operate. For enforcement-heavy strategies, remember that a single strategic filing—like Germany for European control or Singapore for Southeast Asian influence—can sometimes provide broader practical protection than multiple scattered applications.

Don't overlook practical factors either. If key inventors might leave and compete from their home countries, you may want protection there. Some countries even offer preferential treatment in government contracts for patent holders, adding unexpected value to your portfolio.

Two Paths Forward

There are two fundamental approaches to international filing, each with distinct advantages and drawbacks that should align with your company's circumstances and priorities.

Route 1: Direct National Filing involves filing applications directly in each target country's patent office within the one-year Paris Convention deadline mentioned at the start of this post. This means all foreign patent office fees and overseas agent fees come due immediately at filing. While initial costs are higher—averaging around $6,000 for EPO and Japan filings, and $3,000 for most other countries—you'll also face annual maintenance fees starting at about $200 per year and rising to $1,500 annually depending on how long examination takes.

The payoff for this front-loaded investment is speed. Your applications enter examination queues immediately, leading to faster patent grants and earlier enforceable rights. You'll also face rejections sooner if they occur, and you must resolve formalities like powers of attorney and other documentation at the start.

Direct filing typically works best for large companies with established budgets, applicants certain about their target countries, or those needing enforceable rights quickly—particularly when dealing with highly novel inventions where prior art risks are lower.

Route 2: PCT Filing offers a dramatically different approach. Under the Patent Cooperation Treaty, in which about 157 nations participate, you file a single international application through the USPTO, which costs about $3,500 (mostly USPTO and World Intellectual Property Organization fees). The USPTO (or another agency you select) conducts an international search and provides a search report that gives you an early preview of potential prior art problems. If issues emerge, you can centrally amend your claims before entering national phases, and these amendments can apply to all subsequent national filings.

With the PCT, you don't enter national phases until 18-19 months after your priority date, deferring all costs discussed under Route 1 above, and giving you more time to assess markets, confirm the viability or utility of the invention, refine strategy, or secure funding. However, this delay means entering examination queues much later, ultimately slowing your path to granted patents.

PCT filing is particularly attractive for early-stage companies managing cash flow, applicants still uncertain about target countries, or those less concerned about speed—especially when earlier rejections might need disclosure to investors or public markets.

The route you choose often reflects your company's maturity and circumstances as much as the technology itself.

The European Patent Office Advantage

The EPO deserves special attention as it offers centralized examination across 25 countries. After a patent is granted, you validate only in countries where you need protection—typically Germany, the UK, the Netherlands, and France for maximum impact. Despite Brexit, the UK remains part of the European Patent Convention system. A further, multi-country Unified Patent (UP) option can also be chosen at validation. The nuances of whether to select or opt out of the UP are beyond the scope of this post; consult your patent attorney for advice if European coverage is important.

Managing the Reality of Costs

International patent filing becomes expensive quickly, but strategic thinking can control costs. Focus on English-language jurisdictions where possible to avoid translation expenses, or obtain translation quotes from several vendors; translation fees are a significant profit center for overseas law firms and filing agents. Consider different filing strategies for your core innovations versus secondary patents. Remember that you'll face ongoing annual taxes in each country, so every filing decision compounds over time.

The key is treating patent filing as an ongoing business decision, not a one-time legal task. Regular portfolio reviews ensure you're maintaining protection where it still makes commercial sense while abandoning patents that no longer serve your business objectives.

Your international patent strategy should evolve with your business, balancing immediate protection needs against long-term market opportunities and cost constraints.