Outlier Patent Attorneys

Top Mistakes Inventors Make With Provisionals


Collectively, we've written hundreds if not thousands of provisional patent applications, and we've read thousands more.

What are the mistakes that we see the most often?

What are the internal policies and procedures that we use to ensure that we don't make strategic mistakes?

Read on to learn more!

As an FYI, our patent drafting software tool, Patent Pending Made Simple, is structured to specifically help you avoid these issue discussed here and more. So you write a high-quality provisional patent application without worrying about mistakes.

The Importance of Provisional Patent Applications

Before diving into common mistakes, let's understand why provisional patent applications are essential. These applications establish an early filing date for your invention, offer 12 months to develop the invention further, and allow you to use the term "Patent Pending."

The United States Patent and Trademark Office (USPTO) provides a comprehensive guide on what provisional patent applications are and why they're beneficial. Despite the apparent simplicity, many inventors err in their provisional patent application processes. Here are some common mistakes.

Insufficient Disclosure

A provisional patent application's primary purpose is to establish a filing date or a priority date for your invention. In the US, and in most countries around the world, we are in a first to file system, which means that the date of your patent filing is considered the date of your invention. However, if you don't adequately describe your in your patent application, then you are not entitled to the filing date as the date of your invention.

In other words, you patent filing is considered insufficient to establish a priority date.

Needless to say, failure to disclose your invention in detail lead to a loss of priority right and can lead to a loss of patent protection altogether. If you are writing a provisional patent application, it behooves you to be as detailed as possible.

Lack of Breadth

It is easy to for inventors to get lost in the weeds of their invention. After all, you have to work through complexities, often at a very granular level, in order to create an invention or solve a problem in a way that no one has before.

At this level, it is sometimes easy to think that all of the various aspects of your invention are required to create a valuable product, which is not always the case.

To broaden a patent disclosure, we recommend identifying "major" or "universal" components that all competitive products will include and patenting those specifically to improve breadth.

Not Describing Alternative Embodiments

Inventors sometimes describe only a single embodiment of the invention. Neglecting to cover alternatives can limit the scope of protection.

When you are knee deep in a problem, it can be easy to forget that there might be other ways to solve the problem or that some of the aspects of your solution are not universally required.

So we recommend that you put on your competitor's hat and think about how they would design-around your invention, and write those up in your patent application. After all, you don't want your patent application to be too narrow.

Not Clearly Distinguishing Between Prior Art and the New Invention

The application should make it clear what is new in the invention as compared to existing solutions. Failure to do so can make it more difficult to argue for the novelty of the invention.

Failure to Describe Best Mode

The "best mode," or the best method known to the inventor for practicing the invention, must be disclosed. Otherwise, the patent could later be invalidated.

Using Patent Profanity

Terms like “Special,” “Peculiar,” “Superior," “Very Important,” have been held to limit the scope of the invention when it comes to prosecution history estoppel, and should be avoided. Other times, identifying a component as “preferred,” can be misconstrued to mean that other components are optional. This can limit the scope of a future non-provisional application.

Procedural and Formal Mistakes

Incorrectly Labelling Figures and Reference Numerals

Consistency in labelling is crucial for clarity and a thorough understanding of the invention. Any inconsistency can lead to confusion and weaken the application.

Not Following USPTO Guidelines

From formatting to the sequence listing, the U.S. Patent and Trademark Office has specific guidelines that need to be followed.

Leaving Fields Blank on Forms

Missing information on official forms can result in delays or, in some cases, a failure to secure the date of filing.

Additionally, waiting until the last minute to transition from a provisional to a non-provisional application can result in rushed, incomplete, or error-filled non-provisional applications. This is particularly important because non-provisionals are more complex and have a lot more formal requirements.

Ignoring Formal Requirements

Although provisional applications are less formal, they still have specific requirements like cover sheets and fees. Overlooking these can result in rejection (USPTO).

Cases Highlighting the Importance of Avoiding These Mistakes

Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co.

The Ariad Pharma v. Eli Lilly case underscored the importance of having a thorough 'written description' in your application. The U.S. Court of Appeals for the Federal Circuit, in an en banc decision, affirmed that the written description requirement is separate from the enablement requirement and is necessary to ensure that inventors have fully conceived and described their invention at the time of filing. The court held that Ariad's patent was invalid because it did not provide an adequate written description of the invention. This case underscores the importance of thoroughly describing an invention in a patent application to demonstrate possession of the claimed invention, thereby providing clear legal boundaries and protecting the rights of future inventors and the public.

Novozymes A/S v. DuPont Nutrition Biosciences APS

The court in Novozymes v. DuPont examined whether the provisional application adequately supported the invention claimed in the later non-provisional application. In this case, claims in the non-provisional application were found not to be adequately supported by the provisional application, causing a loss of the earlier priority date. The court emphasized that a patent must describe the invention adequately and show that the inventor was in possession of the claimed invention at the time of filing. The patent in question was deemed to cover a broad genus of enzymes without providing a representative number of species or common structural features to support the claimed breadth. This case underscores the criticality of providing a detailed, clear, and representative description of the invention in patent applications to validate the claims and safeguard them against legal challenges.

In re Packard, 751 F.3d 1307 (Fed. Cir. 2014)

While primarily about indefiniteness in patent claims, the In re Packard case is a cautionary tale about the level of clarity required in patent applications, whether they are provisional or non-provisional. In particular, The U.S. Court of Appeals for the Federal Circuit upheld the United States Patent and Trademark Office (USPTO)'s rejection of Packard's patent application, citing that the claims were indefinite and thus not in compliance with the statutory requirement of 35 U.S.C. § 112(b). The court emphasized that during patent examination, a lower threshold is applied to uphold the USPTO's rejection for indefiniteness compared to that applied in post-issuance challenges in the courts. The case underscores the importance of drafting clear, concise, and definite patent claims during the application process to avoid rejections based on indefiniteness and highlights the USPTO's role in ensuring that issued patents meet statutory requirements to provide clear notice to the public of the bounds of the patented invention.


A provisional patent application is a critical tool for securing intellectual property rights. Avoiding common mistakes ensures a smooth transition to a non-provisional application and mitigates risks down the line. Always consider hiring a patent attorney to guide you through this intricate process and ensure your application is both complete and accurate.