International Patent Filing Checklist: A Practical Checklist

Document type: Checklist Practice area: Intellectual Property — Patents Jurisdiction: United States and international Last reviewed: 5 September 2026

Part 1 — Before the priority filing

Disclosure audit — do this first, every time:

Has the invention been described publicly anywhere? Conference talk, poster, abstract, published paper, thesis, preprint.
Shown publicly? Trade show, demonstration, customer site visit, video.
Sold or offered for sale? Quotation, purchase order, catalog listing.
Disclosed without a confidentiality agreement to any third party?
Published on a website, a crowdfunding page, a job posting, or social media?
Are there pending submissions — an abstract under review, a paper accepted, a talk scheduled?
If yes to any: the United States grace period under § 102(b)(1) may preserve United States rights, but absolute novelty jurisdictions (EPO, China, most of Latin America) treat the disclosure as prior art. Assess jurisdiction by jurisdiction before filing.
Freeze further disclosure until the priority application is on file.

Ownership:

All inventors identified, including contractors and consultants.
Signed assignments in place from every inventor.
Any joint development, collaboration, or government funding agreement reviewed for ownership, license-back, or march-in terms.
Employee-invention law considered for any inventor employed outside the United States.

Strategy:

Is a patent the right tool, or is this a trade secret (undetectable process) or a design case?
Preliminary view of target jurisdictions.
Budget acknowledged by whoever controls it.

Part 2 — The priority filing

Filed before any further disclosure.
Priority date recorded and circulated: ____________
Foreign filing license confirmed on the filing receipt — required by 35 U.S.C. § 184; absence can invalidate the United States patent under 35 U.S.C. § 185; rules at 37 C.F.R. Part 5.
Rule confirmed and enforced: no application on a United States-made invention is filed in any foreign country first.

Disclosure quality — draft for foreign offices from the start:

Ranges stated explicitly, not just working values.
Alternative embodiments described.
Explicit statements that features may be combined.
Every feature you may later want to claim has literal support.
Enablement and written description sufficient under 35 U.S.C. § 112 — and under stricter foreign standards.
Remember: European added-matter practice means basis you did not write cannot be created later.

Calendar immediately:

Paris/PCT deadline: priority + 12 months = ____________
Internal deadline: priority + 10 months = ____________
Six-month foreign filing period ends: ____________
Publication (18 months from priority): ____________
National phase deadline (30 months from priority): ____________

Part 3 — The priority year

Month 3: confirm the invention is still in the product plan.
Month 3–9: file supplemental priority applications as the invention develops — ranges, alternatives, new configurations. Cheapest scope available.
Month 6: run a prior art search if one was not run before filing.
Month 9: business case review — is this family worth carrying forward?
Month 10 (internal deadline): make the Paris/PCT decision.
Confirm no intervening public disclosure has occurred that would affect the new matter's validity.

Part 4 — The twelve-month fork

Choose the route:

PCT — file one international application under 35 U.S.C. § 361; effect of a national filing in each designated state under 35 U.S.C. § 363; defers per-country cost to month 30; produces an International Search Report; keeps all member states open.
Paris direct — file in each target country by month 12; faster grant; lower total cost if only two or three countries matter.
Both — direct filing where speed matters, PCT for everywhere else.

If PCT:

International Searching Authority chosen deliberately — fee, search quality, downstream treatment by the offices you care about.
Receiving Office selected.
Claims reviewed for unity of invention before filing.
Claim count reviewed against fee structures.
Filed with margin — not on the deadline.

If Paris direct:

Local agent appointed in each country.
Translations commissioned with time to review.
Claims adapted to local format and fee structure.
Every filing confirmed received before the twelve-month date.

Part 5 — The international phase

Month 16–18: read the International Search Report and Written Opinion. Do not file it.
Categorize the outcome:
- Clean — proceed; consider acceleration downstream.
- Fixable — consider Article 19 amendments or a Chapter II demand.
- Serious prior art — narrow, restructure, or abandon now, before national phase spend.
Chapter II demand decision made on the merits and calendared.
Month 18: publication. Business and sales informed.
Competitor watch updated — your publication invites attention.
Continuation and divisional strategy sketched before national phase entry.

Part 6 — National phase entry (month 30)

Decision memo per family:

Invention in two sentences; product or program it covers.
What the ISR said.
Recommended jurisdictions under the jurisdiction strategy; deviations explained.
Entry cost and ten-year total cost of ownership per country.
Approved by the person who owns the budget.

Jurisdiction selection — ask for each country:

Revenue there, actual and forecast?
Competitor manufacturing there?
Would you realistically enforce there?
Non-enforcement value — licensing, procurement, diligence, deterrence?
Ten-year cost justified by the above?

Mechanics:

United States: national stage under 35 U.S.C. § 371 or bypass continuation under 35 U.S.C. § 120 — decision made deliberately.
Local agents appointed in every entered jurisdiction.
Translations commissioned early, from a technically qualified translator.
Translation reviewed against the original by the foreign associate — in most jurisdictions the translation is the operative text and an error is a claim scope error.
Claims adapted per jurisdiction: claim counts, multiple dependencies, two-part form.
Utility model filings considered where available (China, Germany, Japan) for faster enforceable rights.
Every non-entered jurisdiction recorded with the reason.

Part 7 — The quiet years: deadlines that kill cases

Japan: request for examination within 3 years of the international filing date — calendared: ____________
China: request for examination within 3 years of the filing date — calendared: ____________
Other jurisdictions with separate examination requests identified and calendared.
Office action response deadlines tracked per jurisdiction (they differ from United States practice).
European grant: validation deadlines in each state; translation requirements per state.
Unitary Patent vs. classical validation decision made before grant, with European counsel.
UPC opt-out decision made for classical European patents, deliberately.
EPO opposition window: 9 months from mention of grant — calendared both for your patents (defense) and for competitors' patents (attack).
Annuities: begin before grant in most jurisdictions; every case has one named responsible payer.
Continuation/divisional deadlines tracked per jurisdiction.

Part 8 — Prosecution management

One primary foreign associate per jurisdiction, not seven.
Associates instructed with business context, not just "please advise."
Claim strategy set centrally; divergence across jurisdictions is deliberate, not accidental.
Added-matter discipline enforced in every amendment — European Article 123(2)/(3) creates an inescapable trap.
Prosecution history reviewed for statements that could create estoppel in parallel jurisdictions.
Acceleration considered when a business event requires it: Patent Prosecution Highway, positive IPRP, Track One, PACE, green technology programs.
Fee estimates obtained in advance; invoices reviewed annually.
Annual call with each primary associate about the technology and the business.

Part 9 — Portfolio maintenance

Asset register owned in-house, not by any firm — one row per case, with the responsible party and next date.
Annual reconciliation: register vs. outside firm docket vs. annuity service list, case by case, every discrepancy resolved.
Five-year rolling cost forecast: new filings, national phase entries, prosecution, annuities.
Annual portfolio review with authority to abandon.
Review question: would we acquire this asset today at today's remaining cost?
Prune by jurisdiction, not only by family.
Continuations kept pending on strategically important families.
Portfolio mapped to competitor products annually.
Diligence package maintained current.

Part 10 — Transitions and acquisitions

Firm or provider transition:

Transfer case by case with written acknowledgment of responsibility and next deadline.
Both providers on the docket for a 60–90 day overlap.
Full reconciliation 30 days after completion.

Acquired portfolio:

Within 30 days: complete docket obtained; all deadlines in the next 12 months identified; responsibility confirmed; annuity instructions in force.
Within 90 days: assignments recorded in every jurisdiction requiring recordation.
Within 180 days: acquired families run through your jurisdiction strategy and review criteria.
Encumbrances checked: joint development terms, government funding obligations, unexecuted inventor assignments, customer licenses, security interests.

Part 11 — When something has gone wrong

Missed the 12-month Paris date? Restoration of the right of priority is available in some offices on defined grounds within a limited window — act immediately; the standards are strict and the windows short.
Missed the 30-month national phase date? Reinstatement is available in some jurisdictions on unintentional or due-care standards. Jurisdiction-specific and time-limited.
Missed an annuity? Grace periods with surcharges exist in most jurisdictions; restoration after the grace period is possible in some.
Missed an examination request? Usually fatal. Check the specific jurisdiction immediately.
Pre-filing disclosure discovered? Assess jurisdiction by jurisdiction. Consider whether a narrower claim set avoids the disclosure. Consider whether related later-filed matter is unaffected.
No foreign filing license and a foreign-first filing? A retroactive license may be available where the failure was through error and without deceptive intent. Address it before it is found in diligence.
Chain of title gap? Locate the inventor and obtain a confirmatory assignment now, while they are findable.
In every case: document what happened, what was done, and when — and fix the process failure that produced it.