A First Look at Who Files Provisional Patent Applications

Patent.Law083As part of the 1995 patent law overhaul, the USPTO began allowing patent applicants to file provisional patent applications.  Over a decade later, these lower-cost provisional filings have taken hold.  According to PTO annual reports, over 132,000 provisional patent applications were filed in fiscal year 2007. In perspective, that number is over 30% of the number of the 439,000 non-provisional utility patents filed during the same period. This proportion has been slowly rising since 2002 when the provisional applications filing rate was about 27% of the non-provisional rate.[1] That year (2002), the PTO recorded just under 90,000 provisional applications and 332,000 non-provisional patent applications.

Interestingly, in my study of recently issued patents, only 21% reference a provisional application as a parent. (In the study, I look at approximately 15,000 utility patents issued in April and May 2008.) [2] 

Patent.Law085National Tool: Over half of the recently issued patents that listed an assignee indicated that the assignee was a foreign (non-U.S.) corporation or agency.[4]  Although foreign entities are not prohibited from filing provisional applications, the provisional tool was designed to benefit U.S. entities. Thus, it is not a surprise that only 5% of the patents assigned to international applicants were associated with a provisional application while 30% of the patents assigned to a U.S. applicant were associated with a provisional application.  Two countries – Israel and Canada – stood out as filing the highest proportion of provisional parent claims. Both of these countries are known for having patent attorneys with a high level of familiarity with U.S. laws.  Only 2% of the Japanese & Korean patents included provisional parent claims. [Updated June 03 with Corrected Figure]

The provisional application provides a potential extra year of patent eligibility at the end of the term.  Thus, it is also not surprising that new drug inventions – where a potential year at the end of the term is most valuable – have the highest rate of association with a provisional application.[5]  Likewise, patents on electrical and electronic applications had the lowest rate of provisional filing even after excluding the international applications.

The provisional filings appeared to have almost no impact on the pendency time of a patent application as measured by the number of days from filing the nonprovisional to issuance.  This makes sense as no examination takes place until the nonprovisional application is filed.

The following table also provides some interesting comparisons of patent strategy.[6]

Type of Technology< ?xml:namespace prefix ="" o />

Number of Utility Patents in the Sample

Number of Patents Referencing Provisional Parent











Drugs & Medical












Boston Scientific Scimed





Computers & Communications

























Bristol-Myers Squibb




Procter Gamble




3M Innovative Properties




EI du Pont de Nemours




General Electric[7]






[1] This information comes from PTO annual reports for FY 2006 and 2007.

[2] These patents were downloaded on May 30. I excluded the few patents filed prior to the 1995 introduction of provisional patent applications.

[3] In a follow-on study, I will look at published patent applications claiming priority to provisional applications to get some sense of how often folks abandon provisional patent applications.

[4] 6823 were assigned to foreign entity while 6457 were assigned to a U.S. entity. Another 1922 had no listed assignee.

[5] My study included 677 patents having a primary U.S. Classification in a “drug” field and also assigned to a U.S. entity. Of those, 48% were associated with a provisional application.

[6] Note, my assignee ‘scrubber’ is not yet perfect. Thus, it is likely that some patents associated with listed assignees are not included in the table.

[7] Some companies, such as GE hold patents in several different categories – this table looks only at those patents in the particular identified category.

24 thoughts on “A First Look at Who Files Provisional Patent Applications

  1. 24


    PCT patent applications are published with the complete text of any priority documents, including US provisional applications.

    It is therefore a good idea to always file a complete and detailed document as a provisional application unless there are extenuating circumstances such as imminent publication of aspects of the invention, entering negotations, commencing pre-development market research, or extreme shortage of funds.

    It should not be a problem to throw in a few unpolished claims to indicate what you really think is the invention.

  2. 23

    Mr. Palmer and keith,

    Under Rule 53(c)(3) a provisional can be “converted” to a nonprovisional and accorded the original date of the provisional. Filing a non-provisional based on a provisional under 119 can alternatively be done without sacrificing a year of the term. Most opt for the 119 route especially since most make significant revisions to the original provisional before filing the non-prov including adding claims.

    However, in my practice experience, the preparation and filing of a non-provisional based on a provisional is referred to generally as a “conversion.”

    With all due respect, Mr. Palmer, it is common practice to file claims with a provisional, I would be curious why you are worried about estoppel. Claims have no effect in a provisional, they are absolutely not required and not examined for patentability, and don’t get published.

  3. 22

    Alum Palmer and Ed’s approaches make good sense. That should be safe – one only need to ensure that the description filed under pro is as good as a non-pro. Claims or even claims sets may be carved out at a later stage – perhaps when you can afford to spend more time on the pro.

    As a matter of fact the option of pro should be used but only as a last resort.

    Ed, as long as narrowed claims too have support in the description – there should be no problem.

  4. 21

    Ed — whether an estoppel would be created is a good question. I don’t think that there are any cases on point. Does anyone out there have any opinion on this matter?

  5. 20

    I’ve filed provisionals with no claims per se but included a full set in the summary of the invention. I think my reasoning at the time was that I would avoid creating any estoppel if I narrowed those first filed claims by filing narrower claims in the non-provisional…I don’t know if anybody worries about this anymore.

  6. 19

    Personally, my approach has always been to draft the provisional as if it were the complete application, but with no claims. Of course, on occasion it has been expedient to file the original disclosure as a provisional, but I have never recommended doing that if not a matter of necessity. There were murmurs that provisionals with no claims would be no good for foreign priority, but they all came to nothing.

    Now it seems I’m being told that a provisional with no claims might lack written description, but I don’t know why(?). Provided the spec is well written, what’s the problem?

    I’ve never heard of anyone converting a provisional. I can’t think why anyone would. AFAIK it was only included in the statute to satisfy the Paris convention, not because anyone would ever do it. OTOH, converting a (defective) non-provisional to a provisional can make sense, and then it may be converted back again, but that’s a little different.

  7. 18

    Max is right the recent enfocement of written description requirements is somewhat similar to the EPC ban on claiming new subject matter after the fact.

    There was at least one case in the last few years that turned on the fact there was not a clear identification of what the inventor thought was his invention in the provisional. Provisionals must meet all the 112 requirements. There was enablement, just not the ID of the invention that met 112.

    I will try to look up the case cite.

    Claims are not necessary, BUT they are a simple way to identify what the inventor believes the invention to be. They can also cover a wide array of scopes.

    If you write a paragraph summarizing the invention and the focus in the nonprovisional ends up shifting you may be in trouble as well.

  8. 17

    “The 20% statistic would be much more meaningful if it reflected the number of provisionals that are actually converted as opposed to the percentage of issued patents that list a priority claim to a provisional.”

    Do any US attorneys actually “convert” provisionals?

    Honest question. I have never heard of anyone doing it. I have only seen “claiming priority to” in my practice.

  9. 16

    provisional applications are kind of a tool. File a full set of claims, or at least one broad claim and pray that inventor, when he needs the pro for the purpose of claiming priority from it, sticks to subject matter disclosed in it – otherwise God forbid you may end up in trouble

  10. 15

    I’m interested in the invocation of the “written description” requirement. Here in Europe, one often gets the impression that the nearest thing US patent law has to the European ban on adding “subject matter” after the filing date is NOT the corresponding prohibition under US law but, rather, the requirement for a written description of “the invention” at the filing date. Another thing: as Eurodisnae points out above, for ROW, the absence of claims should not hurt Applicant. Must we really include them in the priority document, just for USA?

  11. 14

    Lionel wrote: “If anyone is filing without any claims at all, they are likely going to have trouble with written description requirements related to identifying the invention in the US.”

    Can you provide a case cite?

  12. 13

    The 20% statistic would be much more meaningful if it reflected the number of provisionals that are actually converted as opposed to the percentage of issued patents that list a priority claim to a provisional.


    Not sure why there would be trouble with the written description requirement… but there are other reasons to file with at least one claim. I just can’t remember what they are at the moment, maybe something to do with filing PCT and requesting an ISR.

    But I do remember one thing:

    I really enjoyed the reparte with Marge included below…

    Lionel Hutz: Uh-oh. We’ve drawn Judge Schneider.
    Marge Simpson: Is that bad?
    Hutz: Well, he’s had it in for me ever since I kinda ran over his dog.
    Marge: You did?
    Hutz: Well, replace the word “kinda” with the word “repeatedly,” and the word “dog”… with “son.”

  13. 12

    I assume that anyone filing a provisional at this point is filing it with a full set of claims. If anyone is filing without any claims at all, they are likely going to have trouble with written description requirements related to identifying the invention in the US.

  14. 11

    Well Eurodisnae, many thanks. Abbott is all fine and good for the 60m UK market but I was thinking more in terms of all those other countries who have signed up to Paris and are therefore bound to recognise a priority date only when a claim is directed to the “same” invention as that announced as the invention and enabled in the priority document. Imagine how many courts there are, that will be working in English (language of the prosecution proceedings) as a foreign language, just like the EPO, and will therefore equate “same invention” with “same words”. For that reason, I am not sure that the sophistication of Abbott is going to be found anywhere in mainland Europe.

  15. 10

    Good points Max.

    Better perhaps to quote the relevant part of the Abbot decision:

    225. Evysio submits that the correct approach is to consider the invention in the claims of the patents said to lack priority and decide what they claim to enable the skilled man to do. Then the disclosure of each of the priority documents as a whole must be considered and the question asked “would a skilled man reading their disclosure with the common general knowledge have obtained enough information to work the invention now claimed?” To put it another way, is the disclosure of the priority document limited to specific embodiments or is it capable of more general application?

    226. I do not accept this submission. Enablement is certainly one of the requirements of a successful claim to priority. Such was established by the House of Lords in Asahi Kasei Kogyo Application [1991] RPC 485. However, it is not the only one. The general and overriding requirement was established by the Enlarged Board of Appeal of the EPO in G02/98 Same Invention, [2001] OJ EPO 413; [2002] EPOR 167:
    “The requirement for claiming priority of ‘the same invention’, referred to in Article 87(1) EPC, means that priority of a previous application in respect of a claim in a European patent application in accordance with Article 88 EPC is to be acknowledged only if the skilled person can derive the subject-matter of the claim directly and unambiguously, using common general knowledge, from the previous application as a whole.”

    227. This was explained by the Court of Appeal in Unilin Beheer v Berry Floor [2004] EWCA (Civ) 1021; [2005] FSR 6 at [48]-[50]:
    “48. …….The approach is not formulaic: priority is a question about technical disclosure, explicit or implicit. Is there enough in the priority document to give the skilled man essentially the same information as forms the subject of the claim and enables him to work the invention in accordance with that claim.
    49. Before going to the details of the priority document in this case I should deal with Mr Carr’s submission about the main claim or consistory clause of the priority document, i.e. that although not determinative it is nearly so. That he could not get out of GO2/98 or indeed any other authority. GO2/98 refers to “the previous application as a whole,” not the main claim nor the “main statement of invention” nor the “consistory clause”. Likewise there is nothing in Art.87 which compels or suggests this conclusion. And Art.4H of the Paris Convention is positively against it. The claims (if any—there is no rule that there should be) of the priority document are not determinative. They are just part of its disclosure. For the purposes of priority one just looks at the disclosure as a whole.
    50. If the rule were otherwise one of the main functions of a priority document would be lost. Inventors and their advisors would have to start worrying not only about the technical information disclosed in the document but how it was to be claimed: have I drafted my main claim or consistory clause broadly enough? That is not the purpose of the system: the purpose at this point is to get the information justifying the later claim into a patent office of a Union country. If you do that, you can have your priority, whether you express that in a proposed claim, consistory clause, statement of invention, other text or drawing or in any combination of these. Time is of the essence because the world-wide system (except for the Americans) works on the first to file basis. The detailed framing of a claim based on that information may then be done within the Convention year.”

    228. So the important thing is not the consistory clause or the claims of the priority document but whether the disclosure as a whole is enabling and effectively gives the skilled person what is in the claim whose priority is in question. I would add that it must “give” it directly and unambiguously. It is not sufficient that it may be an obvious development of what is disclosed.

  16. 9

    As long as the risk is understood and suitably “calculated”, fair enough. I would hope that corporate assignees such as those identified above would be capable of that calculation, but smaller clients may have a tendency to hear only the good news (“bargain price patent pending now”) and not heed the bad (“in the end you may have no enforceable rights outside the USA”).

  17. 8

    Eurodisnae makes an important point, but it loses impact because of his use of “supported”. In my experience, US patent attorneys would say on the basis of domestic US law that ANY intermediate generalisation underivable from the pro is nevertheless “supported” by the pro because, conceptually and scope-wise, it lies somewhere between the illustrated embodiment and the broadest statement of invention in the pro. What if the only ROW claim that can be pushed through to issue is NOT for the (Paris Convention) “same” invention as the one in the prio app.? The Paris priority effect is lost, and with it the patent, everywhere in the world except in the USA, even though there was copious “support” in the US provisional.

    Chemistry is different, however, which is another explanation of the popularity of the US pro in that field.

    Not sure about your “poorly considered” Eurodisnae. The perception, fair enough until recently, has been that the US market is worth more than all the ROW put together. Example: there are 320 million potential stent consumers in the USA but nearly 500 million of the (not so) poor blighters, in the EU alone.

  18. 7

    Dennis, I’m one of those US practitioners who spends most of his time in Israel, and my clients could as easily file in Israel and gain the extra year of protection by re-filing at the end of the year. The real advantage of a U.S. provisional is that, if properly drafted (i.e. it’s drafted as though it’s a non-provisional and meets the requirements of 112), it affords an extra year of the grace period under 102(b), and it establishes a 102(e) date.

  19. 6

    “From a UK/European perspective, I’m curious how aware US practitioners are of the potential damage that can be caused by a poorly considered US provisional filing outside the USA.”

    Anyone who has prosecuted an EPO application based on a US specification knows how difficult it is to amend the claims without adding new matter. From such experiences, one should be able to infer that many US provisionals will lack sufficient support under the EPO’s standard.

    However, Applicants who face imminent disclosures, as The Mad Prosecutor notes, or who are unwilling to pay for full patent protection for every idea often make a calculated risk to file bare bones provisionals, like invention disclosures, to at least to have some possibility of protection.

  20. 5


    I would think, or at least hope, that this is well understood.

    As you can well imagine, in some instances there will be a public disclosure tomorrow regardless of what is or is not filed in the patent office. So, a provisional application is filed for the *chance* that an application might be foreign filed, or the *chance* that priority for the later non-provisional application might be established.

  21. 3

    A provisional application can’t be published unless/until a later application that claims its priority is published. Then it will be made publicly available as part of the official public record for the later application. This has to happen in order for the validity of any priority claim to be judged.

    From a UK/European perspective, I’m curious how aware US practitioners are of the potential damage that can be caused by a poorly considered US provisional filing outside the USA.

    Worst case scenario: you file an inventor’s disclosure as a US provisional. The invention is then made public by use, sale, whatever. Assume the provisional does not include any kinds of claims or statements generalising the supposed inventive concept of the provisional filing. If the claims of any subsequent patent application in an “absolute novelty” country are not adequately supported by the provisional filing they won’t be entitled to its priority date and will be anticipated by the applicant’s own disclosure of the invention. Applicant loses all patent rights outside the USA.

    I know from personal experience that some US attorneys are oblivious to this possibility, and wonder how widespread that is.

  22. 2

    No doubt. I have 3 of those 132,000. PTO should publish them once the nonpro based on the pro is received and compartmentalized to an art unit-would put the world on better notice-probably won’t ever happen-sounds expensive. Wait a minute, where are my maintenance fees going anyways.

  23. 1

    You wrote:
    “Two countries – Israel and Canada – stood out as filing the highest proportion of provisional parent claims. Both of these countries are known for having patent attorneys with a high level of familiarity with U.S. laws. ”
    A more accurate statement (at least for Israel) is “Israel is known for having a large number of US-licensed and US-educated practitioners that reside and practice in Israel.” [a total of 53]
    To verify this, check the number of US-licensed practitioners residing in Israel, and check the number of US-licensed pracitioners practicing in, for example, Germany [a total of 27] or Japan [a total of 32] or Great Britain [a total of 17].

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