The book I'm reading ("Patent It Yourself" by Pressman & Blau) says patent applications cannot be edited after submission. In particular, it says:

If your patent application is rejected because of incomplete disclosure, usually there is nothing you can do since you aren't allowed to add any 'new matter' (additional technical information) to a pending application. In other words, you must get it right the first time.

And the reason it gives for why this is the case, is to prevent patents that have already passed through the approval process, from changing. It says:

Without the rule, an applicant could continuously add improvements and modifications, so that you would never know exactly what their invention covers. Imagine looking at a competitor's patent and thinking you are safe, then being sued out of the blue for infringing an improvement they just added!

But if a patent fails the approval process, wouldn't it never be disclosed to the public? Why can't a patent application be edited throughout the approval process before the patent is approved and awarded? And, if an application is rejected, can an inventor submit another application for the same (or similar) invention, hoping that the application will pass approval that later time?

1 Answer 1


A patent can be edited through the prosecution process and generally is, at least in the claims. Claims are re-written, canceled and replaced by different claims but all must be well supported by the content of the application-as-filed.

The issue is not particularly making changes after approval. Of course, after a claim is allowed one might like to just take the gift. But sometimes an allowed claim is amended, risking a new rejection.

The big issue Pressman is taking about is ”new matter”. That is to be sure that only substantive information presented at the time of filing is included. You can’t add a new embodiment or otherwise change the substance of what was presented at the cut-off date that is the date of filing. If you want to keep inventing it’s too early to file. Or, you can file and keep inventing and plan to file a second application. But once if the first application is published (at the 18 month point) it can sometimes be used as prior art to a subsequent filing.

Yes you can refine your ideas and re-submit but prior art may have been published between the two filing dates that makes the twists you are adding to your invention not novel or obvious. If you didn't continue in parallel with the first application you might end up with nothing.

The filing date determines what is and isn’t prior art. There needs to be a cut off and filing is it.

You can fix typos and other errors. In Europe the rule is you can fix an obvious error for which there is a unique and obvious fix. In the other direction an examiner in Europe will ask that the title and abstract be amended to reflect the claims that actually issue.

The U.S. is less strict. However a change the examiner might let go can be argued later in court as new matter to try to invalidate a patent.

  • This is a great answer. Although, I'd amend as "prior art may have developed that makes your invention [not] obvious in the interim[, or might possibly even not novel]" to reflect better the realistic probabilities of these without publication. It is exceptionally rare that one run into a all-over-the-board rejection based on non-novelty. Commented Sep 24, 2022 at 0:19
  • I re-read and made some edits but I am not sure they are exactly on-point to your comment.
    – George White
    Commented Sep 24, 2022 at 0:43

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