I filed a provisional patent for a machine about 6 months ago. But as of now the outcome of the machine is same but the method to achieve that outcome has been changed a bit(i.e some of the features have been added but the final result remains the same).

In the description section of the provisional patent those features have not been added.

Will I be able to add those feature in the patent or my provisional patent will become invalid?

  • 1
    In the US, you can add as much as you want to the regular application (relative to the provisional), but claim by claim only the claims which are described in the provisional application within the meaning of section 112 would get the benefit of the filing date of the provisional application.
    – DavePhD
    Jan 31, 2021 at 17:38
  • Well at my place while filling the patent it was mentioned that claims may or may not be stated. So I did not stated the claims as it was a initial stage of my system. So your comment does not make any sense in my case.
    – tank12
    Jan 31, 2021 at 18:00
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    You should specify what country, because each system is different. In the US, the entire provisional application (all the text and any drawings) would be considered in determining whether or not each claim of the regular application was described within the meaning of 35 USC 112(a).
    – DavePhD
    Jan 31, 2021 at 18:03
  • Not to be too pedantic but - no such thing as a provisional patent. Only a provisional application for a patent. Difference between lightning and lighting bug. Jan 31, 2021 at 21:07

1 Answer 1


As mentioned in a comment, a non-provisional application you file within a year of the provisional application that gets the benefit of the provisional is not at all constrained by the content of the provisional. However, for a claim in the non-provisional to actually get the benefit of the filing date of the provisional, the provisional needs to fully support that claim. It can turn out that some claims get the earlier date and some do not. The criteria for the level of support is not lessened due to it being a provisional.

A non-provisional can get the benefit of multiple provisional so you can file a second provisional right away that adds the new material and when the year is approaching you can file a non-provisional that claims benefit from both.

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