I have two related but distinct inventions, which I have drafted one specification for. What is the best strategy:

  1. file the specification with two sets of claims (which will include more than 20 claim fees), wait for a divisional, and then split the applications, or
  2. file an application with the specification and only one set of claims, but then shortly afterwards file a contination claiming the second invention, for which the claims are effectively in the first, or
  3. file two applications on the same day, with different claims but the same specification. In this case I might want to have a different title and abstract though. Would this trigger a provisional double-patenting objection?

I've looked at continuation-in-part applications, and can't really see why anyone would file one.

  • Is "filing two different applications for two inventions out of the question?"
    – user18033
    Commented May 19, 2018 at 18:57
  • 1
    Well, I guess I could cut the application specification up and remove stuff not directly related to the other invention. But I've found in the past that sometimes when you have two inventions, you can make a third that has parts of the first two - for example a continuation of invention B that also needs some parts of invention A. So I'm looking for more scope in subsequent continuations. On the other hand, I'm sure the USTPO won't be happy if you always file 100 page specifications containing everything but the kitchen sink just in case it's relevant... Commented May 19, 2018 at 19:27
  • patents.stackexchange.com/questions/10595/… is the same question. Still no clear answer though, although George White's response is valuable. Commented May 19, 2018 at 19:31

1 Answer 1


I think the word "related" is the key here. A divisional application generally cannot get an obviousness-type double patenting rejection over its parent/child/sibling. So you will not need a "terminal disclaimer". This means that you will have an easier time selling each patent to a different buyer. Also, if one patent gets a term adjustment, it will stick.

There is another issue. If you file all the claims in one application, the Examiner may decide that it is, after all, one invention. you could save some money. This is not always good, because if they are not the same invention, the Examination process may be confused.

As to Would this trigger a provisional double-patenting objection?.

What causes the trigger is the claims, not the title or the abstract. In order to give such a rejection the Examiner needs to show that the claims in one case are obvious over the other.

If you choose option 2, instead of "for which the claims are effectively in the first", i suggest writing the claims and putting them in narrative form in the original application as filed.

*I assume the issue is only USA. Other countries have other issues. For example, China and India limit the length of chain of divisional applications allowed. Canada is very strict about overlap between claim sets.

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