Is it important to mention the claims in a provisional patent and how will the claims affect the non-provisional patent if I decided to convert it within a year? I have read that you cannot mention the claims in the non-prov patent if you did not write them in the provisional patent. Is that true? I want to write them but they are not easy to write and I am afraid that writing them wrong would hurt my chances on the invention.

  • Just to be precise, there is no such thing as a provisional patent, only provisional applications. Provisional applications are never granted as patents. You need to file a non-provisional application to have a chance at getting a patent.
    – Eric S
    Commented Jun 12, 2020 at 22:20

2 Answers 2


There is no requirement for claims

Provisional applications are not examined, and therefore have no formality requirements. As long as they are validly filed, it doesn't matter precisely what format they are in.

But including claims in a provisional is good

One key purpose of a provisional is to for a later non-provisional or Convention application to be entitled to an earlier date. This only occurs if the invention claimed in each claim of the non-provisional was present in the provisional.

If the claims of the non-provisional match the claims of the provisional, then this is very clear. And this is where the key benefit lies. By having claims in your provisional, you are making abundantly clear that you are entitled to an earlier date.

Conversely, if there are no claims (or claim-like language) in the provisional, there is an increased risk that the claims of the non-provisional will not be entitled to the earlier date. But it all comes down to risk, and if you are careful with your drafting, you can minimise this risk. But why take the risk if you can avoid it simply with claims?

Is it true that you cannot mention the claims in the non-provisional if you did not write them in the provisional?

No. While it may be good practice to match them up, there is no obligation to have claims in the provisional.

In fact, it is not uncommon for you to need to completely redraft the claims for the non-provisional (perhaps due to further development). This is fine. However, having some kind of claims in the provisional may still be beneficial: you're not obligated to use them in your non-provisional, but you can if they are helpful.

Claims are not easy to write

That's true: they are certainly the hardest part of any patent application. But there is a strong argument for starting with the claims before the description. The purpose of the description is to support your claims: it has no real value on its own. So by starting with the claims, you can ensure that the language in the claims is reflected in the language of the description.

If you start with the description (where you have much more literary freedom), you may end up with language which reads well but doesn't quite suit a good claim. It's not impossible to draft claims last, it's just more difficult.

  • 1
    I cannot thank you enough for the clear information. I afraid I will fail the claims part, can you give me an advice. Should I make a clear and well defined draft and leave the claims until I file the non-provisional application. I have already accepted the answer. Though, I want your opinion on this.
    – Rick James
    Commented Feb 15, 2017 at 3:34
  • @RickJames Add some claims now: there is little reason not to. Even if they're not very good, it's not going to hurt you later.
    – Maca
    Commented Feb 15, 2017 at 4:05
  • Hello, Maca. I agree completely with what you say. I particular I agree with your approach in starting with the claims first and having claims in a provisional application. I have however always wondered that if you do have claims in your provisional application and the claims in your subsequent non-provisional application is wider than in the original provisional application if this will not count against you. Could it not be argued that your original provisional application does not support you subsequent non-provisional application? Commented Feb 22, 2017 at 7:54
  • @DeonPHugo I shouldn't think so: the question of support is based on the specification as a whole, and not just the claims. So if the provisional's description supports the non-provisional's claims, there seems to be no question of the non-provisional being entitled to the earlier date. That said, I haven't seen any case law which rules definitely either way, so I may be wrong when it is tested.
    – Maca
    Commented Feb 22, 2017 at 8:37
  • I think technically you are 100% correct. The issue is as you pointed out whether the provisional application supports the subsequent non-provisional application. It does not matter if the support is in the form of a claim in the provisional application or a discussion of the invention in the provisional application. The way I understand it is that you merely look at the provisional application to support the subsequent non-provisional application. It does not matter how it is formulated in the provisional application. Commented Feb 23, 2017 at 17:04

I think, very. As noted in the other answer, there is (probably) no legal requirement for claims. However, the whole purpose of the provisional filing is to give you a date for the invention. If you do not write the claims, chances are you will not actually set out the invention, but only one or a few specific implementations. This can get tricky. A particular issue being that what you consider to be non-essential limitations will be considered to be part of the invention as set out. This is especially a problem in the EPO (and probably more-so in China, which is very literal-minded about support for language in the claims being found in the application as filed), but can also happen in the USA, where they are generally more flexible. The problem is directly caused by the application not clearly setting out what is non-essential.


You invented the 1-2-3-4 cake. you write a disclosure stating:

  • 1 cup (240 mL) butter
  • 1 cup milk
  • 1 teaspoon vanilla extract
  • 2 cups sugar
  • 3 cups flour
  • 3 teaspoons baking powder
  • 3 pinches salt
  • 4 eggs

When you file non-provisional, you realize that milk could be replaced by orange juice. That was not described, so you figure you can get away with a claim that says:

  • 1 cup (240 mL) butter
  • 1 cup liquid
  • 1 teaspoon vanilla extract
  • 2 cups sugar
  • 3 cups flour
  • 3 teaspoons baking powder
  • 3 pinches salt
  • 4 eggs

Sorry, no support. So you say, lets try leaving out the milk altogether. No can do - a cake cannot be made without liquid. Some type of liquid really is an essential element and many patent offices will insist on finding it in the claim. Now you wish the disclosure had said "a liquid such as milk".

Or, you decide that vanilla is really optional, so you write a claim leaving it out. Again, if the disclosure did not say vanilla is optional, leaving vanilla out is not supported by the priority application. You will need to (and probably fail) to prove that somebody reading your disclosure would understand that vanilla is not part of the invention as conceived and described in the provisional application. Now you wish the disclosure had said "an optional flavoring such as vanilla".

And forget about changing the ratios between the ingredients (like cutting away some fat). Again, there is no support for that.

All this could be avoided had you tried to figure out the metes and bounds of the invention you want to protect. Once you do that, drafting reasonable claims (even if formally improper) is a piece of cake. Of course, you would also want to update your disclosure to support your new understanding of what you invented (as opposed to what you implemented).

clarification: I do not mean to suggest that you start by drafting claims. That is very difficult. Instead, after you draft what you think is your disclosure, put in the hard work of figuring out your invention. Then you can draft some claims, and then you need to fix your disclosure so it reflects your understanding of the invention.

A useful tip: Once you have the disclosure written and try to figure out a claim/inventive concept, you can now compare the "claim" to the written disclosure and consider if perhaps your disclosure is too narrow or if your claim is too narrow. I find it much easier to consider the breadth of a claim when both the claim and the disclosure are in writing and can be compared.

Often, the above issues with the provisional filing cannot be cured, due to publication before the non-provisional filing.

The rule to remember is "a disclosure sufficient to invalidate is not always sufficient to (usefully) patent". In this case, if you published your recipe, replacing the milk or leaving out the vanilla is probably an obvious variant. But they are not described, not is the invention set out as not including them. So the same disclosure which is not sufficient to obtain a patent on OJ-based cake, is sufficient to prevent you (or anybody else) from getting one.

This usually manifests as a one-two combination of writing an article, filing it as-is as a provisional application and then publishing.

see also patently-o.

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    The advice to write claims first only works if one understands a little bit about claim writing. If writing claims did not prompt the inventor to think broadly about at least needing some liquid and they just went ahead and claimed their original idea of the 1 2 3 4 cake, the exercise would not produce the insight. It is thinking broadly about what really matters to the invention that produces the result.
    – George White
    Commented Nov 3, 2018 at 23:38
  • @GeorgeWhite, I amended the answer to clarify a suggested order of steps and a tip for helping in figuring out what to claim after writing a disclosure.
    – tilnow
    Commented Nov 4, 2018 at 16:13

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