Patent Search

A patent search is the most effective way to determine whether your idea is patentable before you file a patent application.

What is a Patent Search?

A patent search is a tool for determining the likelihood of obtaining a patent on an idea. A search looks for issued patents, patent application publications, and other published references. This is called “prior art,” and the Patent Office can use prior art to reject a patent application.

A search attempts to find prior art references that might affect the patentability of an invention. An experienced patent attorney can interpret the results of a patent search to determine whether and to what extent an idea is patentable. This provides the client with valuable information to decide whether it makes sense to pursue the patent application, given the cost, time, and risks involved.


Timing is critical on patent searches. They do very little good, if any, when performed after filing a patent application. To obtain the most benefit from a search, conduct a patent search before filing a patent application.

Some clients choose to file provisional applications. In some cases, it makes sense to run a search before filing a provisional. This could avoid filing unnecessary applications on inventions that will never be patentable or will never be protectable enough to justify the costs involved in pursuing the application.

However, other times, filing a provisional is a higher priority than first determining the extent of patentability with a search. For instance, if a client is in a highly-competitive and fast-moving industry, there may be huge benefits in establishing a filing date as soon as possible. In such situations, the client may want to file a provisional application and then conduct a patent search before filing the non-provisional or any foreign patent applications. This could protect the client’s interests in the potential subject matter.

In either case, it is almost always best practice to run a patent search before a non-provisional patent application is filed.


Unfortunately, no patent search is perfect and cannot be a guarantee. It is impossible to find every single reference that could be cited against your application. This is due to a few reasons.

First, some searches are human-run and some are robot-run, but a human eventually reviews the ultimate results. As objective as patentability standards can be, all humans are different and will interpret search results slightly differently. So no pre-filing search will find the exact same results as the search run by the Patent Office.

Second, by law, the Patent Office keeps most applications secret for their first 18 months. This means that no one can find an application filed 17 motnths and 2 weeks ago. However, that application will publish two weeks later and could be cited against a second application, depending on the filing date of that second application. These are sometimes called “submarine” patents because they cannot be found before they eventually rise to the surface.