Provisional Patent Applications: What They Protect, What They Do Not, and How to Keep the Priority Date

Summary. A provisional patent application buys a filing date, a year of confidential time, and the right to say "patent pending," but only for what it actually describes. This article explains what Congress created in 1994, what the statute requires and leaves out, and why the America Invents Act made the filing date far more valuable than it used to be. It walks through the cases in which priority failed, from New Railhead v. Vermeer to Dynamic Drinkware v. National Graphics, and explains the written description and enablement tests that decide every priority dispute. It separates the common myths from the law, maps the open questions (including the effect of provisionals as prior art under the AIA and foreign "same invention" tests), and sets out what inventors, investors, challengers, and counsel should do differently. An extended worked example follows a hardware startup from a pitch-deck provisional to a priority fight, and the article closes with common mistakes, an FAQ, and takeaways.

At 11:40 on a Wednesday night, Dana Okafor uploads a PDF to the Patent Office. It is the fourteen-slide investor deck for her company, Fernhill Fluidics, plus two pages of notes her co-founder typed that afternoon. The deck shows a palm-sized water-quality sensor with a replaceable cartridge, a photo of the prototype, a market-size slide, and a diagram labeled "proprietary self-cleaning flow cell." Demo day is Friday. The filing fee is a few hundred dollars. By midnight she has a receipt with an application number and a filing date, and on Friday the bottom of every slide says "Patent Pending."

Three years later Fernhill is suing a competitor that ships a sensor with a self-cleaning flow cell. The competitor's lawyers have two exhibits. The first is a trade journal article, published four months after Dana's filing, describing the competitor's own cleaning mechanism. The second is Dana's provisional. Their argument is short: the provisional shows a box labeled "self-cleaning flow cell" and nothing about how it cleans itself. The asserted claims recite an ultrasonic transducer pulsed between sampling cycles. If the claims cannot reach back to the provisional, the trade journal article is prior art, the demo-day presentation may be too, and the patent is in serious trouble.

That is the provisional application in one story. It is cheap, fast, informal, and genuinely useful. It also protects exactly what it describes and nothing more, and nobody at the Patent Office will tell you whether it describes enough until someone with a reason to say no reads it years later.

The short answer

A provisional buys a date, not a right. Under 35 U.S.C. § 111(b) it secures a filing date for whatever it discloses. It is never examined, never issues as a patent, and confers no right to exclude anyone.
The date is only as good as the description. A later nonprovisional claim gets the provisional's date under 35 U.S.C. § 119(e) only if the provisional describes and enables that claimed invention as 35 U.S.C. § 112(a) requires. Priority is decided claim by claim.
Twelve months is a hard wall. The nonprovisional (or a PCT application) must be filed within twelve months. A two-month restoration window exists for unintentional delay, but a provisional cannot be extended, and it goes abandoned at twelve months.
The first-inventor-to-file system raised the stakes. Since March 16, 2013, the earlier filer generally wins, and every intervening publication, sale, or competitor filing counts against claims the provisional does not support.
It does not start the patent term. Term runs twenty years from the nonprovisional filing date under 35 U.S.C. § 154(a), so a provisional can push the patent's expiration out by up to a year.
It stays secret unless you rely on it. Provisionals are not published. They become public only when a published application or patent claims their benefit. That keeps a trade secret option alive for a year.
Courts have taken priority away repeatedly. New Railhead, Lockwood, PowerOasis, and Dynamic Drinkware all turn on the same failure: the earlier document did not describe what the later claim covered.

What a provisional application is

The statutory anatomy

A provisional application is a utility patent application stripped down to its disclosure. Section 111(b) requires a specification that satisfies the written description and enablement requirements of § 112(a) and the drawings required by 35 U.S.C. § 113 (drawings "where necessary for the understanding of the subject matter"). It requires a cover sheet identifying it as a provisional and naming the inventors, and a fee. It does not require claims, an inventor's oath or declaration, an information disclosure statement, or formal drafting. The Patent Office's rules, in 37 C.F.R. part 1 (principally §§ 1.51(c), 1.53(c), and 1.16(d)), fill in the mechanics: the filing date is the day the specification and any drawings arrive, and a missing fee or cover sheet can be supplied later with a surcharge.

Several other features follow from the statute:

No examination. Section 111(b)(8) applies the rest of the patent statute to provisionals but excepts them from examination under 35 U.S.C. § 131 and from derivation proceedings under § 135. No examiner ever compares a provisional with anything.
Automatic abandonment. A provisional is abandoned twelve months after its filing date and "shall not be subject to revival after such 12-month period." Section 111(b)(5) allows a request to convert a provisional into a nonprovisional, but conversion is rarely wise because the converted application's term is measured from the provisional's filing date.
No chaining. A provisional cannot itself claim priority to any earlier application, foreign or domestic (§ 111(b)(7)). You cannot stack provisionals to stretch the year.
No design provisionals. The benefit of a provisional is unavailable to design applications. 35 U.S.C. § 172 gives designs a six-month foreign priority period and states that § 119(e) does not apply to designs, and the rules do not accept a provisional for a design. A design strategy is covered in Choosing Between a Design and Utility Patent: A Practical Checklist.

Element	Provisional (§ 111(b))	Nonprovisional (§ 111(a))
Specification meeting § 112(a)	Required (for whatever you want to rely on)	Required
Claims	Not required	At least one required
Drawings	Where necessary to understand the invention	Same
Inventor oath or declaration	Not required	Required, though it may be deferred
Examination	Never	Yes
Publication	Never on its own	Generally at 18 months from earliest priority date
Life	12 months, then abandoned	Until issued or abandoned
Can claim earlier priority	No	Yes
Counts toward 20-year term	No	Yes
Available for designs	No	Yes (design application under § 171)

Where provisionals came from

Before 1995, a United States patent lasted seventeen years from issuance, and foreign applicants enjoyed something American applicants did not. A German company could file at home, claim that German date under the Paris Convention for the Protection of Industrial Property, and file in the United States up to a year later without losing the year from its American term. American inventors had no equivalent domestic placeholder. When the Uruguay Round Agreements Act of 1994 moved the United States to a twenty-year term measured from filing, Congress created the provisional application to level the field: a low-cost, informal filing that would secure a date without starting the term clock. The Federal Circuit recounted that history in New Railhead Manufacturing, L.L.C. v. Vermeer Manufacturing Co., 298 F.3d 1290 (Fed. Cir. 2002), and it explains why the term statute still says that a benefit claim under § 119(e) "shall not be taken into account in determining the term of a patent" (35 U.S.C. § 154(a)(3)).

For most of their first eighteen years, provisionals mattered less than they do now. Under the old first-to-invent system, an inventor who could prove an earlier conception and diligent reduction to practice could sometimes win priority even after filing second. The Leahy-Smith America Invents Act changed that for applications with an effective filing date on or after March 16, 2013. Under the current 35 U.S.C. § 102, lab notebooks no longer establish priority against a competitor; the "effective filing date" defined in 35 U.S.C. § 100(i) does. And the effective filing date of a claim is the earliest application, including a provisional, that is entitled to support that claim. The provisional became the cheapest way to win a race that the AIA made decisive.

The Patent Law Treaties Implementation Act of 2012 added one more feature, effective December 18, 2013: the ability to restore the benefit of a provisional if the nonprovisional is filed within fourteen months rather than twelve and the delay was unintentional. That rule lives in § 119(e)(1) and in 37 C.F.R. § 1.78(b). It is a safety net, not a plan, and as discussed below, it does not rescue foreign rights.

What a provisional actually does

It fixes a date for what it describes

Section 119(e)(1) gives a nonprovisional application filed within twelve months "the same effect, as to such invention, as though filed on the date of the provisional," for an invention "disclosed in the manner provided by section 112(a) (other than the requirement to disclose the best mode)" in the provisional, by an inventor named in the provisional, if the nonprovisional contains a specific reference to the provisional. Each phrase does work:

"As to such invention." The benefit attaches to the invention disclosed, not to the application as a whole. A nonprovisional with twenty claims can have twenty different effective filing dates.
"In the manner provided by section 112(a)." The provisional must contain a written description showing possession of the claimed invention and must enable a skilled person to make and use it without undue experimentation.
"Other than the requirement to disclose the best mode." Since the AIA, a provisional need not disclose the inventor's best mode to support priority, and failure to disclose best mode is no longer a ground for invalidating a claim under 35 U.S.C. § 282(b)(3)(A). Best mode remains a formal requirement of § 112(a), so drafters still include it.
"By an inventor or inventors named in the provisional." At least one inventor must be common to both applications. Getting inventorship roughly right on the cover sheet matters, though it can be corrected.
"Specific reference." The nonprovisional must identify the provisional by application number, in an application data sheet, within the time set by 37 C.F.R. § 1.78 (generally the later of four months from the nonprovisional's filing or sixteen months from the provisional's). Miss that and the benefit claim can be lost or require a petition.

It holds the grace period and the race

Under the AIA, a claim is anticipated by anything "described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date" (§ 102(a)(1)), and by another's patent or published application that was "effectively filed" before it (§ 102(a)(2)). The provisional date, if the claim is supported, moves the line back. The inventor's own disclosures within a year before that date are excepted by § 102(b)(1)(A), and a third party's disclosure of the same subject matter after the inventor's own public disclosure is excepted by § 102(b)(1)(B). But the grace period only helps in the United States, and only against disclosures the inventor actually made. A provisional filed before any disclosure avoids the question entirely. The doctrine is set out in full in Prior Art Under the America Invents Act: Section 102, the On-Sale Bar, Public Use, and the One-Year Grace Period.

It supports foreign priority

A United States provisional is a "regular national filing" for Paris Convention purposes. Section 119(a) governs priority claims into the United States, but the reciprocal rule abroad lets an applicant file in Paris Convention countries, or file a Patent Cooperation Treaty application under 35 U.S.C. § 365, within twelve months and claim the provisional's date. The twelve-month foreign deadline is not extended by the domestic fourteen-month restoration rule. PCT restoration of priority exists under the PCT regulations, but whether it is available, and on what standard, depends on the receiving office and each designated office. For the international sequence (PCT, national phase at thirty months under 35 U.S.C. § 371, and the costs), see International Patent Filing: The PCT, Paris Priority, National Phase, and Foreign Prosecution.

It delays the term clock

Because term is measured from the nonprovisional filing date, a patent that claims a provisional's benefit can expire up to a year later than it would have if the nonprovisional had been filed on day one. For a pharmaceutical or a platform technology with a long commercial tail, that last year can be worth more than everything spent on the application.

It preserves secrecy for a year

35 U.S.C. § 122(a) keeps applications confidential. Provisionals are never published on their own; the Office makes a provisional available to the public only when a published application or issued patent claims its benefit. A company that files a provisional, learns more, and decides the technology is better protected as a trade secret can let the provisional lapse and lose nothing it had not already disclosed elsewhere. That option disappears once a nonprovisional publishes, which under § 122(b) happens about eighteen months from the earliest priority date, that is, about six months after a timely nonprovisional is filed. The interaction between patents and secrecy is treated in Building a Trade Secret Protection Program from Scratch.

It lets you say "patent pending," truthfully

While a provisional is pending, marking a product "patent pending" is accurate. Once it lapses without a nonprovisional, it is not. 35 U.S.C. § 292(a) prohibits marking "patent applied for" or "patent pending" on an article "when no application for patent has been made, or if made, is not pending, for the purpose of deceiving the public." The intent element is real (see Pequignot v. Solo Cup Co., 608 F.3d 1356 (Fed. Cir. 2010)), and since 2011 only the United States or a competitor with a competitive injury can sue, but penalties run per article (see Forest Group, Inc. v. Bon Tool Co., 590 F.3d 1295 (Fed. Cir. 2009)). Calendar the day the provisional lapses and take the legend down if nothing replaced it. Marking practice generally is covered in Understanding Patent Marking Requirements: A Practical Guide for Practitioners and Entrepreneurs.

What a provisional does not do

The list of things a provisional cannot do is longer and matters more.

It does not give anyone a right to exclude. Only an issued patent can be infringed under 35 U.S.C. § 271. The "provisional rights" of 35 U.S.C. § 154(d), a reasonable royalty for the period before issuance, despite the name, attach to a published application whose issued claims are substantially identical to the published ones and require actual notice. Provisionals are never published, so they never generate provisional rights. As the Federal Circuit put it long ago, filing an application is no guarantee that any patent will issue, and a pending application gives competitors nothing to infringe: State Industries, Inc. v. A.O. Smith Corp., 751 F.2d 1226 (Fed. Cir. 1985). The willfulness consequences of pre-issuance knowledge are discussed in Willful Patent Infringement and Enhanced Damages After Halo: Knowledge, Opinions of Counsel, and Section 298.

It does not tell you whether the invention is patentable. No examiner reviews eligibility under 35 U.S.C. § 101, novelty, or nonobviousness under 35 U.S.C. § 103. A filing receipt says the Office received paper. It says nothing about whether a patent will ever issue.

It does not reserve subject matter it fails to describe. This is the central limitation, and the cases below are about it. Material added in the nonprovisional gets the nonprovisional's date. An obvious variant of what the provisional described is not "described" for priority purposes.

It does not last longer than twelve months. There is no extension, no revival, and no second provisional that relates back to the first. A second provisional filed later gets its own later date for everything in it.

It does not cure disclosures made before it was filed. A provisional filed after a public demo does not help in countries without a grace period. Europe's novelty standard is absolute, subject to narrow exceptions for abuse and certain exhibitions. If foreign protection matters, the provisional must come before the first public disclosure, not after.

It does not fix ownership. The applicant on a provisional cover sheet does not decide who owns the invention. Title starts with the inventors and moves only by assignment, as the Supreme Court emphasized in Board of Trustees of Leland Stanford Junior University v. Roche Molecular Systems, Inc., 563 U.S. 776 (2011). A company that files a provisional naming a consultant as co-inventor, with no signed present assignment, may not own what it filed. Chain-of-title problems are treated in Patent Ownership, Assignments, and Standing: Chain-of-Title Problems That Sink Cases.

It does not authorize foreign filing. An invention made in the United States cannot be filed abroad within six months of the U.S. filing without a foreign filing license under 35 U.S.C. § 184 and 37 C.F.R. part 5. The filing receipt usually grants one, but not always. Filing abroad without it can bar a United States patent under § 185, and violations involving secrecy-order inventions carry penalties under § 186.

The priority test: what "disclosed in the manner provided by section 112(a)" means

Every priority dispute about a provisional reduces to one comparison. On one side is a claim, usually written years later by a litigator-minded prosecutor who knows what the accused product looks like. On the other is the provisional, often written in a hurry by an engineer. The question is whether the provisional, read by a person of ordinary skill in the art as of its filing date, describes and enables the invention of that claim.

Written description: possession, shown on the page

The en banc Federal Circuit confirmed in Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co., 598 F.3d 1336 (Fed. Cir. 2010) that written description is a requirement separate from enablement. The test is whether the disclosure "reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date." Possession means possession shown in the document, not in the inventor's head or lab. Ariad's patent claimed methods of reducing NF-κB activity in cells; the specification described the goal and hypothesized classes of molecules that might achieve it, but did not adequately describe any that did. The claims failed.

Three corollaries matter most for provisionals:

A result is not an invention. In University of Rochester v. G.D. Searle & Co., 358 F.3d 916 (Fed. Cir. 2004), the patent claimed a method of selectively inhibiting the COX-2 enzyme by administering a compound that does so, but disclosed no such compound. Describing what you want to happen, without describing the thing that makes it happen, does not show possession. A provisional that says "the controller optimizes flow using a proprietary algorithm" has the same problem.
Obvious variants are not described. In Lockwood v. American Airlines, Inc., 107 F.3d 1565 (Fed. Cir. 1997), the patentee's chain of earlier applications did not describe the full combination later claimed. The court held that entitlement to a filing date "does not extend to subject matter which is not disclosed, but would be obvious over what is expressly disclosed." One shows possession "by describing the invention, with all its claimed limitations, not that which makes it obvious." The drafter's instinct that "any engineer would know you could also use a stepper motor" is not a written description of a stepper motor.
A genus needs more than a species. Where a claim covers a family (any fastener, any polymer, any machine-learning model), the provisional must describe enough representative species, or common structural features, to show possession of the family. A provisional describing one embodiment supports claims to that embodiment and, at most, to close variations. The Federal Circuit made the same point outside biotechnology in Gentry Gallery, Inc. v. Berkline Corp., 134 F.3d 1473 (Fed. Cir. 1998), where claims broad enough to put a sofa's recliner controls anywhere were not supported by a specification that described them only on the center console, and in Tronzo v. Biomet, Inc., 156 F.3d 1154 (Fed. Cir. 1998), where generic claims to a hip-socket cup could not reach back to a parent application that described only a conical one.

Drawings count. In Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555 (Fed. Cir. 1991), the court held that drawings alone may provide the written description that supports later claims. That is good news for a provisional with careful figures and bad news for one with a single block diagram.

Enablement: the full scope, without undue experimentation

The provisional must also teach a skilled person how to make and use the claimed invention. Amgen Inc. v. Sanofi, 598 U.S. 594 (2023) reaffirmed that if a patent claims an entire class of things, the specification must enable a skilled person to make and use the entire class. Amgen's claims covered every antibody that bound a particular site on the PCSK9 protein and blocked it from binding LDL receptors, a genus that could include millions of candidates, while the specification described twenty-six and offered "roadmaps" for finding more. The Court called those trial-and-error instructions "little more than two research assignments." Some experimentation is acceptable, under the factors of In re Wands, 858 F.2d 731 (Fed. Cir. 1988), but the more one claims, the more one must enable.

For a provisional, Amgen has a practical meaning. The broad claim a company will want at month twelve must be enabled by the provisional, not just by the nonprovisional. If the nonprovisional adds the examples that make the genus enabled, the genus claim takes the nonprovisional's date.

Who has to prove what

The Patent Office does not decide whether a claim is entitled to a provisional's date unless an examiner needs to (because intervening art appears). So there is no presumption that a patent's claims are entitled to an earlier date. In PowerOasis, Inc. v. T-Mobile USA, Inc., 522 F.3d 1299 (Fed. Cir. 2008), the patentee's claims to a vending system for telecommunications access recited a "customer interface." The original application described an interface on the vending machine itself; only a later continuation-in-part described an interface on the customer's own laptop. When the accused infringer showed intervening prior art, the burden shifted to PowerOasis to come forward with evidence that its claims were supported by the earlier application. It could not, and the claims were invalid. The same allocation applies to provisionals: the challenger shows prior art that predates the nonprovisional; the patentee must then come forward with evidence that the provisional supports each claim; the challenger keeps the ultimate burden of persuasion on invalidity.

Cases where priority failed

New Railhead: the drawings that did not show the angle

Gregg Cox developed a drill bit for horizontal directional drilling through rock. The commercial embodiments were sold in the spring and summer of 1996. Cox filed a provisional in February 1997, within a year of those sales, and a nonprovisional in November 1997, more than a year after them. Under the pre-AIA on-sale bar, everything turned on whether the patent's claims were entitled to the February 1997 date.

The claims recited a bit body "angled with respect to" the sonde housing. The issued patent said so in so many words and showed it in a figure, describing an angle on the order of fifteen degrees. The provisional did not. It discussed a "heel-down method of attachment," "high included angle offsets for directional steering," and the bit's theory of operation, and it concluded with two drawings of the bit and its housing. New Railhead argued that a skilled reader, looking at the drawings and the text together, would understand the angled relationship. The Federal Circuit disagreed in New Railhead. For the nonprovisional to get the provisional's date, the provisional's specification must describe the invention and the manner of making and using it in terms that would enable a skilled artisan to practice "the invention claimed in the non-provisional application." The provisional did not describe the angle, so the claims got the November 1997 date, the 1996 sales were more than a year earlier, and the patent was invalid.

The lesson is concrete. A feature that becomes a claim limitation needs to be stated in the provisional, in words, and shown in a figure if it is structural. Theory of operation and hints do not substitute for a description of the structure.

Lockwood and PowerOasis: the continuation chain as a cautionary tale

Lockwood and PowerOasis involved earlier nonprovisional applications rather than provisionals, but § 119(e) uses the same § 112(a) standard as § 120, and courts apply the same analysis. Both show the same pattern: claims written later to cover a broader or different arrangement, an earlier document that described one specific arrangement, and an intervening reference that becomes invalidating once the date is lost. The Federal Circuit applied that pattern again in Anascape, Ltd. v. Nintendo of America Inc., 601 F.3d 1333 (Fed. Cir. 2010), reversing a jury verdict against Nintendo because the asserted claims, which covered game controllers with multiple input members, were not supported by a priority application that described a single input member. In each case the patentee had something real on the earlier date. It simply was not what the patentee later claimed.

Dynamic Drinkware: the provisional as a weapon against someone else

Provisionals also matter when a patent is cited against you. Under the pre-AIA rule in § 102(e), an issued United States patent was prior art as of its filing date, and the Federal Circuit held in In re Giacomini, 612 F.3d 1380 (Fed. Cir. 2010) that a reference patent could be prior art as of its provisional's date. But what must the provisional show?

In Dynamic Drinkware, LLC v. National Graphics, Inc., 800 F.3d 1375 (Fed. Cir. 2015), Dynamic petitioned for inter partes review of National Graphics' patent on a method of making lenticular images, relying on a patent issued to Raymond. National Graphics showed that it had reduced its invention to practice before Raymond's nonprovisional was filed, so Dynamic needed the earlier date of Raymond's provisional. Dynamic compared National Graphics' claim to the Raymond provisional. It did not compare Raymond's own claims to the Raymond provisional. The Federal Circuit affirmed the Board's ruling that Dynamic had failed to carry its burden: a reference patent is entitled to its provisional's date only if the provisional supports the claims of the reference patent as § 112 requires. Once the patent owner produced evidence of its own earlier date, the burden of production shifted back to the petitioner, and the burden of persuasion never left it.

Dynamic Drinkware has two lessons. For challengers, an invalidity case built on a reference's provisional date needs a claim-support chart for the reference, not only an anticipation chart for the target. For patentees, it is another reminder that a provisional is evaluated against claims, not against a general sense of what the inventor was working on.

Disclosure, the grace period, and the twelve-month clock

A provisional is usually filed because something is about to happen: a demo, a pitch, a conference talk, a customer pilot, a sale. Understanding which events count as prior art, and when, is what makes the filing date meaningful.

Public disclosures

A paper, a website, a slide deck posted online, or a poster at a conference can all be "printed publications." The test is public accessibility. In In re Hall, 781 F.2d 897 (Fed. Cir. 1986), a single doctoral thesis indexed and shelved in a German university library qualified. In In re Klopfenstein, 380 F.3d 1345 (Fed. Cir. 2004), a poster displayed for about two and a half days at professional meetings, with no copies handed out and no confidentiality expectation, was enough. A demo-day deck shown to an audience of strangers and posted to an event website is very likely a publication.

Public use and sale

The public-use bar reaches back to the nineteenth century. In Egbert v. Lippmann, 104 U.S. 333 (1881), a corset spring given to one person and worn out of sight for years was a public use; in City of Elizabeth v. American Nicholson Pavement Co., 97 U.S. 126 (1877), a test stretch of pavement laid on a public road for six years was experimental and not barred. The on-sale bar is triggered by a commercial offer for sale of an invention that is "ready for patenting," which Pfaff v. Wells Electronics, Inc., 525 U.S. 55 (1998) held can be shown by a reduction to practice or by drawings or descriptions sufficient to enable a skilled person to practice the invention. There is an irony here worth stating plainly: if a company has materials good enough to support a strong provisional, its invention is probably ready for patenting, and a commercial offer starts the clock.

The AIA did not change what "on sale" means. In Helsinn Healthcare S.A. v. Teva Pharmaceuticals USA, Inc., 586 U.S. 123 (2019), the Supreme Court held that a sale to a third party that is required to keep the invention confidential can still place the invention "on sale." And an inventor's secret commercial exploitation of a process, such as selling products made by a secret method, has long been treated as a forfeiting use, under the reasoning of Metallizing Engineering Co. v. Kenyon Bearing & Auto Parts Co., 153 F.2d 516 (2d Cir. 1946). For a deeper treatment, see Finding, Qualifying, and Using Prior Art: A Practical Guide.

Pitch decks and the confidentiality question

Founders ask whether pitching investors is a disclosure. The answer depends on the audience and the terms. A private meeting with a small number of investors who understand the material is confidential is generally not a public disclosure, and courts have treated limited distribution under an expectation of confidentiality as non-public. A pitch competition with a public audience, a recorded webinar, a deck uploaded to a data room with no access controls, or a deck emailed to dozens of strangers is a different matter. Many venture investors will not sign nondisclosure agreements, which is a reason to file before pitching, not a reason to pitch without filing. The NDA mechanics are in Drafting Enforceable Non-Disclosure Agreements for Technology Transactions.

A second, newer disclosure channel deserves mention: pasting invention details into a public generative AI tool to "help write the provisional." Whether that is a public disclosure depends on the tool's terms and data handling, and it can also undercut trade secret protection for anything not ultimately patented. See Trade Secrets and Generative AI: Reasonable Measures, Prompt Leakage, and Vendor Terms.

The twelve-month clock and the weekend rule

The nonprovisional must be filed within twelve months of the provisional's filing date. If the last day falls on a Saturday, Sunday, or federal holiday in the District of Columbia, § 119(e)(3) and 35 U.S.C. § 21(b) extend it to the next business day. A nonprovisional filed in months thirteen or fourteen can still claim the benefit through a petition under § 1.78(b) showing the delay was unintentional, with a fee. Foreign filings do not benefit from that rule. The safest practice is to calendar month nine as the decision date, month eleven as the filing date, and month twelve as the deadline.

A provisional as prior art against others

Once a nonprovisional that claims a provisional's benefit is published or issues, it becomes prior art under § 102(a)(2) as of its "effectively filed" date, which § 102(d) defines as the date of the earliest application to which it is "entitled to claim a right of priority or benefit" that "describes the subject matter." That means a well-written provisional is not only a shield; it is also a sword against later filers, effective for the subject matter it describes, as of its own date.

Myths and reality

Myth	Reality
"A provisional is a cheap patent."	It is not a patent and will never become one. It expires in twelve months unless replaced.
"Patent pending means competitors cannot copy."	Nothing can be infringed until a patent issues, and provisionals produce no § 154(d) royalties. "Patent pending" has deterrent value only.
"I can add improvements to the nonprovisional and keep my date."	You can add them, but each added feature gets the nonprovisional's date. Claims relying on it lose the provisional's benefit.
"Anything is enough to get a date."	Anything is enough to get a filing receipt. Only a § 112(a) disclosure supports priority, and nobody checks until it matters.
"Claims are not allowed in a provisional."	Claims are not required, but they are allowed and usually helpful.
"I can file another provisional to extend the year."	A new provisional has its own date. The first one's date cannot be extended.
"My provisional will be published and anyone can read it."	It stays confidential unless a published application or patent claims its benefit.
"The grace period means order does not matter."	The U.S. grace period covers only your own disclosures and their echoes, and most foreign countries have none.
"I can use a provisional for my product design."	Provisionals are unavailable for design patents.
"Small entity status is automatic for startups."	Status must be established and asserted, and a false assertion of entitlement to a fee reduction made without good faith exposes the applicant to a fine of at least three times the underpayment under 35 U.S.C. § 41(j).

Splits and open questions

Does Dynamic Drinkware survive the AIA?

Dynamic Drinkware interpreted pre-AIA § 102(e). The AIA's § 102(d) speaks of an application "entitled to claim" a priority or benefit that "describes the subject matter." The Patent Office's examination guidance (MPEP § 2154.01(b)) has taken the view that, under the AIA, a reference is effective as of the earliest application that describes the subject matter relied on, without separately requiring that the reference's claims be supported by that earlier application. The Federal Circuit has not squarely resolved whether its Dynamic Drinkware claim-support requirement carries over. Until it does, a challenger relying on a reference's provisional date should build both showings, and a patentee facing such a reference should test both.

How much detail does software or AI need?

Software and machine-learning inventions are where thin provisionals are most common. A block diagram showing "data in, model, prediction out" rarely describes possession of a specific model architecture, training regime, or data pipeline. Post-Amgen, claims to "any model trained to" achieve a function invite enablement challenges as well as eligibility challenges under Alice Corp. v. CLS Bank International, 573 U.S. 208 (2014). Courts have not drawn a bright line for how much algorithmic detail a priority document needs, which means drafters should assume more is required, not less. Eligibility issues are covered in Patent Subject-Matter Eligibility After Alice: A Practical Checklist.

Foreign priority uses a different test

A provisional that supports U.S. claims may still fail to support priority abroad. The European Patent Office asks whether the claimed subject matter is "directly and unambiguously derivable" from the priority document as a whole (the "same invention" test from Enlarged Board of Appeal decision G 2/98). In 2023, in consolidated decisions G 1/22 and G 2/22, the Enlarged Board held that entitlement to claim priority is presumed, rebuttably, which eased a separate problem of who may claim priority from a U.S. provisional filed in the inventors' names. Neither decision lowers the "same invention" standard. A provisional written for the U.S. possession test should also be written to survive a stricter literal comparison.

AI-assisted inventorship

Only natural persons can be inventors, Thaler v. Vidal, 43 F.4th 1207 (Fed. Cir. 2022). The Patent Office issued guidance in February 2024 applying the joint-inventorship factors of Pannu v. Iolab Corp., 155 F.3d 1344 (Fed. Cir. 1998) to AI-assisted inventions, requiring a significant human contribution to each claim. Provisionals for AI-assisted work should record what each named person contributed, because the provisional's inventor list must share at least one person with the nonprovisional. See AI-Generated Inventions: Who Owns What the Machine Creates?.

Does a claim set in the provisional help?

Nothing requires claims, and some practitioners omit them to avoid creating a record that later reads as a narrow description of "the invention." Most experienced drafters include at least a set of draft claims because writing them forces the specification to describe every limitation, gives a foreign office a clearer "same invention" comparison, and reveals gaps while there is still time to fill them. The law does not settle the point; practice tilts strongly toward including them.

What this means for each participant

Inventors and startups

File before the first public disclosure, and treat that date as the deadline. Work backward from the demo, the conference, the launch, or the first sales pitch.
Write the provisional as if it were the nonprovisional without claims. Every feature you might claim, every alternative a competitor might use, every parameter range, and every figure.
Do not let the deck be the disclosure. A deck is marketing. Attach it if you like, but the body must explain structure, operation, and alternatives.
Paper ownership first. Present-tense assignments ("hereby assigns") from every contributor before filing. See Employee Invention Assignment Agreements: Drafting for Enforceability Across Jurisdictions.
Use the year. Build, test, and file a follow-up provisional for each improvement, then a nonprovisional that claims all of them.

Investors and acquirers

Diligence that ends at "they have a provisional on file" has not started. Ask for the provisional itself, the nonprovisional (if any), and a priority chart showing which claims rely on which document. Check the twelve-month deadline, the inventor list, the assignments, and whether anything was disclosed before the filing date. The IP Due Diligence Checklist for Mergers and Acquisitions: A Practical Checklist has the broader list.

Accused infringers and patent challengers

Every patent that claims a provisional's benefit invites a priority audit. Pull the provisional from the file history, chart each asserted claim limitation against it, and look for intervening art between the provisional and the nonprovisional: the patentee's own publications and sales, competitor products, and trade press. PowerOasis shifts the burden of production to the patentee once you show the intervening art. In an inter partes review, the same allocation applies, as Dynamic Drinkware holds. See Patent Post-Grant Proceedings: IPR, PGR, and Reexamination at the PTAB.

Counsel

A provisional prepared by a lawyer or agent is a professional product, and a bad one can become a malpractice claim years later. Practitioners before the Office are bound by the rules in 37 C.F.R. part 11, including competence and communication duties. When a client insists on filing a deck the night before demo day, document the advice that the filing may not support later claims, and schedule the follow-up provisional before the meeting ends.

Extended worked example: Fernhill Fluidics

Return to Dana Okafor and Fernhill Fluidics, and run the story twice: once as it happened and once as it should have.

What happened

Month 0 (March). Dana files the deck plus two pages of notes as a provisional ("P1"), naming herself and her co-founder, Theo Marchetti, as inventors. The notes say the sensor "uses a self-cleaning flow cell to prevent biofouling" and that "cleaning can be mechanical, chemical, or acoustic." There is one figure: a block diagram with a box labeled "self-cleaning flow cell." No assignment from Theo is signed; the company's founder agreement says he "agrees to assign" future inventions.

Month 0, two days later. Fernhill presents at a public demo day. The recorded presentation shows the prototype and says the cell "cleans itself acoustically." The video is posted online that week.

Month 4. A competitor, Brackwater Instruments, publishes a trade journal article describing a flow cell cleaned by an ultrasonic transducer.

Months 6 to 10. Fernhill's engineers, led by a contract engineer named Priya Raman, settle on a piezoelectric transducer pulsed at 40 kHz for 200 milliseconds between sampling cycles, with a duty-cycle controller that skips pulses when turbidity readings are low. Nobody files anything.

Month 12. Fernhill files a nonprovisional ("N1") with a detailed description of the transducer, the pulse schedule, and the controller, and claims the benefit of P1. Claim 1 recites the transducer "pulsed between sampling cycles." Claim 9 adds the turbidity-based skip logic. Priya is not named as an inventor.

Year 3. N1 issues. Fernhill sues Brackwater, which ships a pulsed-ultrasonic flow cell.

How the challenge goes

Brackwater's priority analysis proceeds claim by claim.

Claim 1. P1 mentions acoustic cleaning as one of three options and shows a box. It does not describe a transducer, where it sits, how it is driven, or any timing relative to sampling. Under Lockwood, the fact that pulsing between samples might be obvious from "acoustic cleaning" does not make it described. Under New Railhead, a structural limitation absent from the provisional's text and figures is not supported. Brackwater argues claim 1 is entitled only to N1's date. The burden of production shifts to Fernhill under PowerOasis; Fernhill's expert says a skilled person would "understand" the transducer arrangement from the word "acoustic." That is the argument the Federal Circuit rejected in New Railhead.
Claim 9. The skip logic was invented in month eight. It cannot have P1's date under any theory.
Intervening art. With N1's date, the Brackwater article (month 4) is prior art under § 102(a)(1). Fernhill's own demo-day video (month 0) is within the one-year grace period as to N1 and is excepted under § 102(b)(1)(A) as Fernhill's own disclosure. Fernhill argues that § 102(b)(1)(B) also removes Brackwater's article because Fernhill publicly disclosed "the subject matter" first. But the demo video said only "cleans itself acoustically"; the exception covers only the same subject matter, and Brackwater's article disclosed the specific transducer arrangement that Fernhill's video did not. Under the Office's guidance, the exception does not reach the more specific later disclosure.
Inventorship and ownership. Brackwater notes that Priya conceived the pulse schedule recited in claim 1 and the skip logic in claim 9. Under 35 U.S.C. § 116 and the Pannu factors, she is likely a joint inventor. Correction under 35 U.S.C. § 256 is available, but if Priya never assigned her rights, she co-owns the patent and can license Brackwater. Theo's "agrees to assign" language raises the Stanford v. Roche problem: a promise to assign in the future may not transfer legal title on its own.
Foreign rights. Fernhill filed a PCT application at month twelve claiming P1. In Europe, the demo-day video is novelty-destroying for anything it disclosed, and the priority claim to P1 fails for claim 1 under the "same invention" test. Fernhill's European case is effectively gone.

The result: claim 1 is likely anticipated or obvious over the Brackwater article, claim 9 faces an obviousness fight with the article as the primary reference, and Fernhill's leverage collapses into a settlement discussion about inventorship.

What should have happened

Two weeks before demo day. Dana and Theo meet with counsel for a ninety-minute invention capture session. They sign present assignments ("hereby assign") to Fernhill. Counsel records three cleaning approaches the team has considered and asks for each: where the component sits, what drives it, how its operation is timed, and what parameters matter.

One week before demo day. Counsel files P1: a twenty-five-page specification with eight figures. It describes the flow cell geometry, a piezoelectric transducer mounted on the cell wall, frequency ranges (with a preferred range), pulse durations, pulsing between sampling cycles and alternatives (continuous low-power operation, pulsing on a timer), mechanical wiper and chemical flush alternatives, and the materials tested. It includes fifteen draft claims ranging from a broad "flow cell comprising an acoustic actuator coupled to a wall of the cell" to a narrow claim reciting the pulse schedule.

Demo day. The presentation reveals no more than P1 describes. The posted video postdates P1, so it is not prior art to any claim P1 supports, and it describes nothing P1 does not already cover.

Month 8. Priya develops the turbidity-based skip logic. Fernhill obtains her assignment and files P2 describing it, naming Priya.

Month 11. Fernhill files N1 claiming P1 and P2, and a PCT application claiming both. Claims 1 through 8 are supported by P1; claims 9 and 10 by P2. The application data sheet lists both provisionals.

Year 3. Brackwater's priority audit finds that claim 1 is entitled to P1's date, which predates its article. The article is not prior art to claim 1. The case is about infringement, not about Fernhill's paperwork.

The cost difference between the two versions is a few thousand dollars and two weeks of calendar time. The value difference is the patent.

Common mistakes

Filing the pitch deck. Marketing slides describe benefits, not structure. Use them as an appendix at most.
Describing results instead of means. "Reduces fouling by 90 percent" is a result. The transducer, its placement, and its drive signal are the means. The provisional needs the means.
One embodiment, broad claims later. If you will want a genus claim, describe several species and the common features that make them work.
Figures that do not show the claimed feature. New Railhead turned on an angle that the drawings did not clearly depict. Draw what you will claim.
No follow-up provisionals. Improvements made after filing need their own filing before they are disclosed.
Missing the twelve-month date abroad. Domestic restoration does not restore Paris priority. Calendar the foreign deadline separately.
Ignoring the foreign filing license. Filing abroad directly, or letting a foreign co-inventor file at home first, without a license can bar the U.S. patent.
Unsigned or future-tense assignments. Fix them before filing, not in diligence.
Leaving "patent pending" on after the provisional lapses. It becomes false marking exposure.
Asserting entity status without checking. Small entity status is lost by licensing or assigning to a large entity; micro status has income and filing-count limits.

Frequently asked questions

How long does a provisional last? Twelve months from its filing date. It cannot be extended. A nonprovisional filed within fourteen months may still claim its benefit if the delay was unintentional and a petition is granted, but foreign priority deadlines are not extended by that rule.

Can I file a provisional myself? Yes. Inventors can file through the Patent Office's Patent Center system. The risk is not the filing mechanics; it is whether the document describes what you will later claim. A self-filed provisional is far better than nothing before a disclosure, and far worse than a complete one.

Will the Patent Office tell me if my provisional is inadequate? No. The Office checks formalities only. Whether the provisional supports a claim is decided later, usually by an examiner confronted with intervening art or by a court or the Patent Trial and Appeal Board in a validity challenge.

What does a provisional cost? The government filing fee is modest and depends on entity status, with discounts for small and micro entities under 35 U.S.C. § 41(h) and 35 U.S.C. § 123. The USPTO adjusted many patent fees effective January 19, 2025. Under that schedule the provisional filing fee is $325 for an undiscounted filer, $130 for a small entity, and $65 for a micro entity; check the current fee schedule before filing. Attorney fees for a well-drafted provisional commonly run from a few thousand dollars into five figures, depending on complexity and how complete the inventor's materials are.

Should I file a provisional or go straight to a nonprovisional? File a provisional when you need a date quickly, expect to improve the invention within the year, want to delay costs or the term clock, or are unsure whether to patent at all. Go straight to a nonprovisional when the invention is mature, you want examination to start, or you plan to seek accelerated examination.

Does a provisional protect me against someone who files first with the same idea? Only for what your provisional describes. If both applications describe the same subject matter, the earlier effective filing date generally wins. If a competitor's filing describes a feature your provisional did not, your claims to that feature take your nonprovisional's date, and the competitor may be first.

Can I keep the invention secret if I decide not to patent? Yes, if you let the provisional lapse without a published application claiming it. The provisional itself is never published. Once a nonprovisional claiming it is published, the provisional becomes available too.

Takeaways

A provisional is a date-stamp for a disclosure. Its value depends entirely on what it discloses.
The test for priority is the § 112(a) test applied to each later claim: possession on the page and enablement of the full scope.
Courts take priority away when the earlier document described something narrower or different from what was claimed. New Railhead, Lockwood, PowerOasis, and Anascape, Ltd. v. Nintendo of America Inc., 601 F.3d 1333 (Fed. Cir. 2010) follow the same pattern.
File before disclosing anywhere you might want foreign rights, and before any commercial offer if the invention is ready for patenting.
Use the year: follow-up provisionals for improvements, assignments from every contributor, and a conversion plan by month nine.
Calendar the lapse date for marking and the twelve-month foreign date separately from the domestic deadline.
Challengers should audit priority claim by claim; patentees should assume someone will.

For the step-by-step filing process, see Preparing and Filing a Provisional Patent Application: A Practical Guide. For a task list, see the Provisional Patent Application Checklist: A Practical Checklist. For templates, including an invention capture form, a written description audit worksheet, and a conversion calendar, see the Provisional Application Toolkit: Invention Capture Templates, Written Description Audits, and Conversion Calendars.

This document is general information, not legal advice for any particular situation. Patent rights depend on the specific facts, documents, and dates involved, and fee amounts and Patent Office procedures change; consult a registered patent practitioner before relying on any filing strategy.