When to file: the clock starts earlier than you think

The short answer to when to file a patent application: before the first public disclosure of the invention. That means before the paper, the preprint, the conference poster or the pitch to an investor who has not signed anything. The United States gives inventors a one-year grace period for their own disclosures. Most of the rest of the world does not.

This article is for founders and academic researchers who are about to talk about their work in public. It covers the U.S. first-inventor-to-file rules and grace period, why Europe is stricter, what counts as a disclosure, provisional and PCT deadlines, and a filing calendar.

Key takeaways

• Since March 16, 2013, the United States has awarded patents on a first-inventor-to-file basis. The filing date is what counts.
• The U.S. grace period covers your own disclosures made one year or less before you file. It is a safety net, not a plan.
• Europe applies absolute novelty. A disclosure anywhere, in any form, before the filing date counts against you, with two narrow exceptions.
• Preprints, posters, theses, public grant abstracts, demos and decks shown without confidentiality can all be disclosures.
• A provisional application holds a filing date for 12 months. A PCT application filed within that window keeps foreign options open until about 30 months from the first filing.

Why does the filing date matter so much?

Under the America Invents Act (AIA), the U.S. patent system compares your claims against everything that was public before your effective filing date. Being the first to invent no longer decides who gets the patent. If the relevant information became public before you filed, it can block you, even if that information came from your own lab.

The rule sits in 35 U.S.C. § 102(a)(1). It says you cannot get a patent if the claimed invention was “patented, described in a printed publication, or in public use, on sale, or otherwise available to the public” before the effective filing date. That earlier information is called “prior art.” These rules apply to applications with any claim whose effective filing date is on or after March 16, 2013.

There is no geographic limit: a talk in Tokyo counts the same as one in Boston. And the date that matters is the date of an application that actually describes what you later claim.

How the U.S. one-year grace period works, and where it stops

The U.S. grace period says your own public disclosure is not prior art against you if you file within one year of it. It covers disclosures by you, a co-inventor, or someone who learned the invention from you. It does not reset the clock, it does not cover different subject matter, and it does nothing for you outside the United States.

The grace period lives in § 102(b)(1), which has two parts. Under § 102(b)(1)(A), a disclosure made one year or less before the effective filing date is excepted if it came from the inventor or a joint inventor, or from someone who obtained the subject matter from them. Under § 102(b)(1)(B), a third party’s later disclosure is also excepted if you publicly disclosed the same subject matter first.

The second exception is narrower than it sounds. MPEP § 2153 explains that it shields only the subject matter you actually disclosed. If a competitor later publishes an obvious variant, or a species you never described, that material is still prior art. If you post a preprint on one qubit control pulse shape and another group then publishes a different pulse family, your preprint does not shield you from theirs.

There are other limits too:

• Independent work. If someone else publishes first, the grace period does not help.
• Proof. If a paper lists more authors than the application lists inventors, you may need a declaration under 37 CFR 1.130.
• Foreign rights. A disclosure the United States forgives can still destroy novelty abroad.

Why Europe and most other countries are stricter

Europe uses absolute novelty. An invention is new only if it is not part of the state of the art, and the state of the art includes everything made available to the public anywhere, in any language and in any form, before the filing date. Europe has no general grace period, only two narrow exceptions limited to six months.

Article 54 of the European Patent Convention (EPC) defines the state of the art as everything made available to the public “by means of a written or oral description, by use, or in any other way” before the filing date. The EPO’s examination guidelines add that there is no restriction on geographical location, language or manner of disclosure. An oral presentation counts.

Article 55 EPC provides the only relief. According to the EPO Guidelines, Part G, Chapter V, there are two instances, and only two: a disclosure that resulted from an evident abuse against the applicant (such as a breach of confidence), and display at an officially recognized international exhibition. The disclosure must have happened no earlier than six months before the actual filing date. A conference talk or journal article is neither.

Some countries are more forgiving. Japan, for example, extended its grace period for exceptions to lack of novelty from six months to one year in 2018, but the applicant must claim the exception at filing and submit proof within 30 days. Do not assume any such rule will rescue a disclosure.

What counts as a public disclosure?

A public disclosure is anything that makes the invention available to people who could understand it, without a duty of confidentiality. The test is accessibility, not intent or audience size. Papers, preprints, posters, theses, public grant abstracts, demos, websites and unprotected investor meetings can all qualify. Under U.S. law, some confidential sales count too.

Papers, preprints and abstracts

A preprint is a publication the moment it is posted, and so is a meeting abstract. MPEP § 2128 treats online documents, including social media posts, as printed publications if people interested in the field could find them, and it dates them from when they were posted. The safe deadline is the first posting, not the journal’s publication date.

Talks and posters

A poster displayed for a few days at a meeting, without confidentiality limits, can be a printed publication even if no one takes a copy. A purely oral talk with no slides is not a printed publication in the United States, but it may still make the invention “otherwise available to the public.” In Europe, an oral disclosure counts outright.

Theses and dissertations

A thesis that is cataloged and shelved in a university library can be prior art from the date it became accessible. Graduate students should check the library’s embargo options and file before deposit when an invention is involved.

Grant abstracts

Funded-project abstracts are often public. NIH RePORT, for example, lets anyone search a repository of NIH-funded research projects. Describe the goal in the public abstract, not the specific solution, such as the exact linker chemistry or waveguide geometry.

Investor decks, demos and sales

A deck shown to a room of investors with no confidentiality obligation can be a disclosure, and a deck posted online certainly is. Many VC firms will not sign NDAs, so keep enabling detail out of the slides until you have filed. My post on what investors ask about your patents covers what to show instead. Demos, website copy and offers to sell raise the same issue.

What an NDA does and does not do

A signed confidentiality agreement generally keeps a document from being a printed publication. It does not protect against the “on sale” bar. In Helsinn v. Teva (2019), the Supreme Court held that a sale to a third party obligated to keep the invention confidential can still be prior art. Before a supply or license deal, file first.

Where does a provisional application fit?

A provisional application is a lower-formality U.S. filing that secures a filing date for 12 months. It is not examined and does not need formal claims. To keep the date, you must file a nonprovisional application, a PCT application, or both within 12 months, and the later claims must be supported by what the provisional actually says.

The benefit comes from 35 U.S.C. § 119(e). The USPTO’s provisional application page notes that the 12-month period cannot be extended, although restoration may be possible up to 14 months under 37 CFR 1.78 if the delay was unintentional. Do not plan on that.

The common failure is a thin provisional: a slide deck filed the night before a talk. It secures a date only for what it describes well enough to satisfy 35 U.S.C. § 112(a). A deck that shows a result but not how to get there may not support the claims you need. A separate post covers common provisional application mistakes in more depth.

PCT timing: the 12-month and 30-month deadlines

The Patent Cooperation Treaty (PCT) lets one international application preserve your rights in its 159 contracting states. You file it within 12 months of your first application to claim that earlier date. You then decide country by country, generally by 30 months from the first filing date, where to pursue patents.

There is no international patent. As WIPO’s PCT FAQ explains, grant stays with national and regional offices. The PCT buys time and a search report. WIPO publishes the application shortly after 18 months from the priority date.

Put the 12-month date in the company calendar on the day you file.

A practical calendar for when to file a patent application

The safest habit is to tie a patent review to each disclosure deadline you already track: abstract submissions, preprint posts, thesis deposits, grant submissions and investor meetings. Count back from the earliest of those dates, file a complete application before it, and then calendar the 12-month and 30-month deadlines from that filing.

Before any public disclosure, run through this checklist:

1. List every upcoming disclosure: abstracts, preprints, posters, theses, grant abstracts, demos and pitch meetings.
2. Mark the earliest one. That is your real deadline, not the conference date.
3. Decide whether foreign protection matters. If it might, assume no grace period.
4. Write down what the invention is, how to make and use it, the data, and the alternatives you have tried or expect to work.
5. Agree on inventorship before the author list is set. Authors and inventors are not the same group.
6. File before the disclosure, and check that the application covers everything the talk or paper will show.
7. Calendar the 12-month and 30-month deadlines on the day you file.

For a university lab, that means involving the technology transfer office early; for a spin-out, it is part of the work I describe on the startups and university spin-outs page. What to write down depends on the field. My post on what can be patented in quantum computing gives an example of how hardware and algorithm claims differ.

Frequently asked questions

Can I publish my research and still get a patent?

Yes, if you file first. If you publish before filing, the United States may still allow a patent if you file within one year, because of the inventor-disclosure grace period in 35 U.S.C. § 102(b)(1). Most other countries, including those under the European Patent Convention, will treat your own paper as prior art. Filing before publication keeps every option open.

How long after a public disclosure can I file a patent application?

In the United States, up to one year after your own public disclosure; after that, it becomes prior art against you. In Europe, a disclosure before filing generally destroys novelty, with only narrow six-month exceptions for evident abuse and certain international exhibitions. Japan allows one year if formal requirements are met. Check each country before relying on its rule.

Does a conference talk count as public disclosure?

It can. In Europe, an oral presentation is expressly part of the state of the art. In the United States, slides or a poster shown without confidentiality limits can be a printed publication, and a talk can make the invention otherwise available to the public. Abstracts often go online weeks before the event, so that is the real deadline.

Is filing a provisional application enough before I present?

It secures a filing date for what it describes. A provisional filed before a talk protects the material it explains well enough for someone skilled in the field to make and use the invention. If the talk reveals details that are not in the provisional, those details are not covered. You must also file a nonprovisional or PCT application within 12 months.

Does an NDA protect me if I share my invention with investors?

A signed confidentiality agreement generally keeps the information from becoming a public disclosure. Many investors will not sign one, though, and an NDA does not prevent the U.S. “on sale” bar from applying to a confidential sale. The safer approach is to file first and keep enabling technical detail out of decks shared before filing.

If you are deciding when to file a patent application ahead of a conference, a thesis deadline or a fundraise, I am happy to talk it through.

This article is general information, not legal advice, and reading it does not create an attorney-client relationship. Patent law changes and every situation differs. Please talk to a patent attorney about yours.

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