My basic question is: to which degree can an imperfectly written but substantially complete PCT application still be upgraded/fine-tuned (by a good attorney) in the first couple of months after filing?

Here are more details:

I have a provisional filed with USPTO on June 1, 2017, and I plan to follow it up by June 1, 2018 with a PCT application to claim the provisional's priority date.

I have enough cash to pay the PCT filing fee with the USPTO as Intl Search Authority (about $2000) but I do not have enough cash right now to pay attorney fees. I have done a prior art search and read many patent texts as well as some instructional books and websites, so I feel reasonably confident to be able to put together specs and claims that are not half bad. That being said, I realize that I won't do as good a job as when working with an attorney. However, by fall, we will have incorporated, raised capital, and an attorney at our side.

Therefore the big picture is:

  • I need to act now to keep the 2017 priority date alive
  • I want to keep costs as low as possible until the fall
  • I want to maximize options/salvageability at least for another 6 months until more funds will be available

I understand that the PCT timeline is:

  1. 4 months after PCT filing date, the intl search report (ISR) gets issued
  2. Amendments to specifications and claims can be made under Article 34 up to either (1) 3 months after the ISR is sent; or (2) 22 months from the priority date (i.e. 10 months after the PCT filing, so in my case April 1, 2019).
  3. That means if I have incorporated and raised funds by fall 2018, I can then work with an attorney to refine the application and strengthen specs and claims to the degree of what's there (I understand that no new content can be added).

Is that picture correct?

  • Do you know just how much money a PCT-application costs when nationalizing? It's 12 more months to gather literally tens of thousands of dollars if you want to go anywhere where a translation is needed and still a lot for english speaking countries. Maybe a good US-non prov. would be worth more than a "not half bad" PCT. Make sure you know the cost estimate and when those costs incurr.
    – user18033
    Commented May 8, 2018 at 8:51

5 Answers 5


The international phase

There's no requirement to respond to the ISR or written opinion. While you are provided with the opportunity to file article 19 or 34 amendments and provide arguments, and these may be considered at the international phase, many countries will just re-search and re-examine your application anyway during the national phase. You may therefore have amended your application in the international phase to address prior art that the USPTO or EPO don't consider relevant. Moreover, the requirements for amendments are so different in different countries, that you might want to defer filing amendments until the national phase anyway.

For this reason, once the PCT application is filed, it is an entirely valid approach to do nothing until national phase entry. You would of course likely want to review the prior art identified in the ISR and satisfy yourself that you can overcome it before filing the national phase entry applications though, otherwise you'd just be throwing good money after bad.

Thus, even if you had funds from day 1, you might still want to pursue a strategy of tactical waiting.

For completeness, I should note of course that some applicants and attorneys prefer to argue their case throughout the international phase, with a view to getting a clear IPRP. The benefit is that this may simplify national phase applications (particularly outside of the USPTO and EPO). This is a valid approach too, and there is no right or wrong way.

The national phase

You have pretty wide discretion with the claims when entering national phase (and these can be freely changed in a continuation/divisional anyway). So if your PCT application claims are suboptimal, this can be easily addressed. The bigger problem is the description: once you get to the deadline for filing a PCT application, there's nothing more you can do. It is therefore critical that your description is in good shape.


Note that after filing the PCT, you won't really need to do anything until December 1, 2019 (30 months after the PCT app priority date), at which point you will incur costs going into the various national stages.

After the June 1, 2018 window closes, your application content will be effectively "locked down". Therefore, it's not possible to rectify lack of description while still maintaining your priority date. You may be able to add/remove features from the claims during prosecution, but outside the US (esp. EPO), this may require explicit disclosure of such claim feature combinations.

Basic advice would be this (which I see is redundant with that of others):

  • Include extensive description of those things you think are unique and are looking to claim -- what it is, how it works, and why it's useful. You should have some idea of the distinctions based on what you've seen in the prior art.
  • Determine which specific embodiments/combinations of features you think are important and would like claim scope over. Make sure to provide descriptions of those particular embodiments, and preferably have figures demonstrating each (esp. for mechanical inventions). The claims you actually submit are not as consequential, as they can be modified later.

You will not be able to change the specification or drawings in any manner other than to correct a typo (an error in the text that is clearly an error and clearly only has one way to be fixed can be changed) or improve the legibility of a drawing. Your attorney will be stuck with your errors of omission and commission. As another answer mentions, the claims can be changed latter.


Perhaps you can look at it this way. How many countries do you really plan to enter once the PCT Application enters national phase entry. If its only USA or few handful more (say Canada and Europe), then you can altogether avoid the PCT. Instead, by June 01, 2018 prepare the non-provisional application with a professional US patent agent / attorney and use that application to be filed in Europe and Canada by the said date. My thinking is if you can avoid the PCT application filing fees, you can use that money to hire a patent attorney to file on your behalf at least in the US. The PCT mostly buys you time, but then again it really depends in how many countries you want to really really want to protect your invention.


I have a provisional filed with USPTO on June 1, 2017, and I plan to follow it up by June 1, 2018 with a PCT application to claim the provisional's priority date.

I feel reasonably confident to be able to put together specs and claims that are not half bad.

At the EPO (and probably many other jurisdictions) the priority will probably not hold. Any changes introduced at first in the PCT application will have the new filing date then. Which basically also means, for jurisdictions other than the US, where a priority document doesn't need to basically literally support the following application, you don't have to care for the 1 year period because it doesn't benefit you.

It would then be possible to now file only a US-non.prov. and file the PCT application within 6 months, before any of the US applications publishes, so that they are not prior art for most, if not all, other jurisdictions.

Please be advised that this is dangerous and understand the implications completly before deciding! But if you wouldn't feel comfortable filing the exact text of the provisional as a PCT application, ignoring the one year priority might not do too much damage.

This can only work if you have not published anything about your invention! Otherwise, that would be prior art.

(If you file a PCT application now, however, you would have to withdraw it prior to filing another one without priority, because it would be prior art retrospectively if it publishes. You would then not have the priority not even in the US.)

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