"...from November 5, 2020, there is a New Mexican IP Law in force, which has established new legal concepts and has brought light to some Practice areas which before this New Law, were imprecise or not entirely clear. The New Mexican IP Law has established rules and filing exceptions, which to consider when filing divisional patent applications..." Uhthoff

I just can't get my head around what is meant by the term "divisional patent applications"

  • I just can't get my head around what is meant by the term "ivisional patent applications" Dec 18, 2021 at 21:34
  • This isn't unclear, it merely used a technical term known only to a few, even on this site. Once that term was explained (in the answer) it is perfectly clear and should not be closed. Dec 19, 2021 at 0:32
  • should NOT be closed? -OR - Once that term was explained (in the answer) it is perfectly clear and should be closed. Dec 20, 2021 at 15:16
  • Should not be closed. A user suggested that the question be closed because it was "unclear". Questions that are successfully answered are not closed because they have been answered. Questions are normally closed when there is some problem with them and no answers should be made until the problem is fixed, or when they are off-topic and no answer should be made at all. When a user votes that a question be closed, sometimes others post comments indicating why they think it should not be closed.. Dec 20, 2021 at 15:32
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    Fine with me. I was not aware of this. I am still learning how to correctly use this Site. Dec 21, 2021 at 21:24

1 Answer 1


A divisional application is one that is a spin-off if a patent application that claims subject matter that is fully supported in a previous patent application’s specification and drawings if required but is not claimed in the parent application. The divisional gets the benefit of the filing date of the earliest relevant parent patent application.

An example would be an application that discussed two inventive ways to make a toaster that toasted bread to desired degree automatically. One uses a camera to look at the bread and pops the toaster when a set degree of brown is detected and the other uses an electronic “nose” to sense the vapors from burning the bread. Both are well supported with details in the specification and drawings.

If there is one claim to one invention and one claim to the other invention the examiner will declare that you do not have “unity of invention” and require you to pick between them and cancel any claims to the other. In the U.S. this has different name with slightly different criteria.

If you want to pursue the unselected invention it will be via a divisional application. It is a new application that states that it is a divisional of patent application 1235667 and claims priority from it.

It could also be a case where two inventions are described but only one is claimed. You not get any notice from the examiner but can later chose to file a divisional.

There are rules as to when a divisional can be filed and these have been recently changed in Mexico. A rule that many jurisdictions have is that it can only be filed while the parent application is still pending, Mexico tightened up those rules.

  • Maybe an example would be helpful? Dec 19, 2021 at 0:17
  • My question was an attempt to come up with an acceptable trial question. The truth is that only idle curiosity wonders the meaning of this term since I have never imagined making a patent application. Thank you for explaining how this Site is designed to work. I hope my confusion is not messing anything up. Dec 21, 2021 at 21:28
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    A good question must actually be a question. Until I copied your comment into the question it was not remotely a question. "What makes something a divisional patent application as opposed to some other type of patent application" would be a straightforward question. Nothing wrong with a link to news about the change in Mexican law as something that motivated the question. As originally written it would have been closed as "not a question". Note that Ask Patents is an SE site specifically for patent questions, but patent questions are fine here on SE law. Dec 22, 2021 at 0:42

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