Prior to investing in a patent application, we generally recommend a patent search be performed. A patentability search is designed to obtain copies of the most pertinent patents available. The preliminary patentability search is only about 80% percent accurate for several reasons. Some prior publications are not properly classified in the U.S. Patent and Trademark Office; some publications that contain relevant information are not a part of the records of the Patent and Trademark Office. Not all pending United States patent applications are publicly available. Therefore, there is always the possibility that another patent will issue later which will have an effect on the patentability of an invention (see 35 U.S.C. § 102 (reproduced above)). It is difficult for the Patent and Trademark Office to insure that all of these patents are properly classified for searching. Patentability searches are designed to get as much information as possible for the amount of money involved. It is always possible that a closer reference could be found by expending a substantially higher amount of money. Typically, several thousand dollars would be required for a very comprehensive search of all possible art areas. Since this is higher than the usual cost of applying for a patent, the patentability search is generally restricted to computer searching.

Inventors who wish to do some investigating on their own before paying to have a patentability search performed by a professional searcher can search on the Internet by visiting the site at www.freepatentsonline.com (this site is user friendly and allows for one to download the patents in a pdf format), or the site at www.uspto.gov (this site has images of all U.S. Patents and the full text of all U.S. Patents from 1976 through the present), or the site https://patents.google.com/ or the site at http://ep.espacenet.com (this site has over 45 million patents from over 70 countries). This is time-consuming, and will not likely tell the inventor whether the invention might be patentable – it might only let the inventor know that there is a patent exactly like their invention. If the invention is a product, an inventor may want to start the searching at Amazon.com, then conduct a search of the internet in general, and finally try the patent websites. Regardless of the results, a patent attorney should still be consulted before a final decision is made on whether or not to file a patent application. Also, if the search does not reveal any patents which, in the opinion of the patent attorney, render the invention unpatentable, a search by a professional searcher should be performed before a patent application is prepared.

A patentability search is conducted to give an indication of whether an invention might be patentable. It is not designed to determine whether practicing an invention might infringe another patent. To get an indication of whether one can practice an invention without infringing another patent (or a published patent application), a freedom-to-operate search should be conducted.