What Is a Patent Search?

A patent search involves looking through patent documentation to find out if your invention is new and potentially patentable. A patent gives you a monopoly on the use, sale, manufacture, and licensing of your invention for 20 years.

Why Are Patent Searches Important?

If you invent something, you might be entitled to a patent, but only certain inventions and ideas are patentable. In the United States, three patent types are available, and they determine the length of your patent protections, whether the patent can be extended, and finer legal points. These include:

  • Utility. For inventions with practical applications
  • Plant. For asexually reproducing plant species
  • Design. For strictly ornamental objects

Patent searches are important because the United States Patent and Trademark Office (USPTO) will only grant patents on inventions that meet three criteria. The idea must be:

  • Novel
  • Non-obvious
  • Useful

thorough patent search addresses the first point by proving your invention is new and potentially worthy of a patent. If, however, your invention or something similar is already publicly available, you might not get a patent.

Patent searches are part of the body of research that goes into a patent application. The purpose of this research is to find all prior art. Prior art is the publicly available documentation of ideas that might be relevant to your invention. This includes existing patents, current patent applications, non-patented products or processes, ideas described in academic and technical journals, etc. While a patent search will not find all prior art — because some is probably not patented — a thorough search will point you toward prior art that might not have been obvious when your research began.

The smart inventor will begin patent and prior art searches with the earliest version of the invention. Because a patent can only be issued for a new product, invention, or idea, discovering that your idea has already been dreamed up saves you the time and money of pursuing an idea that you cannot patent.

Early searching allows you to focus your efforts on the parts of your invention least like prior art. At the same time, if an invention gets a patent, a thorough patent application including relevant prior art strengthens the patent because the USPTO will have determined that your invention is novel despite similar prior art. A thorough patent search also limits the possibility that your idea infringes on other patents since many "new" ideas are patented but never put on the market.

Strong patents are important for seeking investors and fighting off competitors. While doing a patent search is quicker and less expensive than it once was, your competitors can find prior art and relevant patents just easily as you can. If your patent search misses important prior art that a competitor later finds, your patent might be unenforceable. A patent search will help you get a deeper technical understanding of your product, the market, your competitors, and companies who might be interested in licensing your invention.

Don't ignore or fail to document prior art similar to your idea. While you might be disappointed to learn that your idea already exists, knowing that your patent will likely not be granted can be a huge time- and money-saver, and you can abandon or change your idea before investing much time and money into it. Also, don't assume that if you find no prior art your idea is truly new. Assume that you are looking in the wrong place. Finding no prior art is not proof that your invention is "new."

You must show to the USPTO any prior art that you believe is relevant to your idea. Submit this with your patent application in a document called an Information Disclosure Statement (IDS). The USPTO uses this information in its decision to grant a patent. Because documenting and submitting your references is your legal obligation as an inventor, failing to disclose relevant prior art might have consequences such as:

  • Your patent might be unenforceable.
  • You might be liable for infringing on other patents.
  • You might be guilty of inequitable conduct or fraud on the patent office.

If the USPTO accepts that your invention in new, useful, and non-obvious, it will grant you a patent. This patent gives the claims outlined in your patent application legal validity and is difficult to challenge. If someone wants to challenge your patent, they might try to find prior art that you might have missed in your research, which is yet another reason to do a thorough patent search. Including all relevant prior art gives you a legal advantage and makes the USPTO more likely to grant your patent.

Before You Begin

You have several options when doing a patent search:

  • You can hire professional patent researchers.
  • You can find a Patent and Trademark Resource Center (PTRC) and have their reference librarians help you.
  • You can do the search yourself.

A professional is more likely to find prior art than you and will do so quicker. On the flip side, a professional can be very expensive. If you use a PTRC, services are typically free (some fees might apply), but the nearest PTRC might not be nearby or have convenient hours. If you do your own patent search, the main benefit is that it is inexpensive and can be done on any computer with an internet connection. It might, however, be very time-consuming.

If you do your own patent search, first brainstorm a list of relevant keywords. As with any search engine, online patent searches give results only as good as the keywords they are fed. Therefore, good keywords improve your chances of finding relevant information. Because there are millions of patents, the best keywords might save you hours of searching through irrelevant patents. Important questions to ask yourself — and answer in the most specific technical terms — when creating your keyword list are:

  • What is my invention's purpose?
  • Is my invention a process or a product?
  • What is my invention made of?
  • How is my invention used?
  • What is the nature of my invention?

The most obvious keywords, however, might not be helpful. Such keywords tend to return too many hits or a lot of irrelevant hits. Think of less obvious words and concepts related to your idea, or think of different ways to describe your idea. For example, a search for "lawnmower" might return thousands of hits, but a search for "electric grass trimmer" might reduce the results to a manageable number.

Familiarizing yourself with historical terms and industry jargon and consulting technical dictionaries and thesauruses will help you find more keywords. For example, many engineering disciplines use jargon unlikely to be obvious keywords to anyone but insiders. Knowing these terms will give you an advantage when doing a patent search. Also familiarize yourself with buzzwords and terminology about a new technology. For example, if your invention involves virtual reality and you fail to research developments in the field of augmented reality, you might not get a patent.

You might research existing products and talk to experts before doing your patent search. By finding products like your invention or products that solve the same problem, you can guide yourself toward patents you might otherwise miss. You will also gain a better feel for the market in which your invention will compete. You might also get a better idea of which parts of your invention are most innovative and patentable and which ones need to be refined. Be aware that some parts of your invention are likely to have already been patented or published.

Good sources of product information that might guide your patent search include:

  • Offline books
  • Periodicals
  • Catalogs

Obsolete products and products in development but not yet on the market might also be prior art, so reading industry journals, historical documents, trade show and exhibition listings, and academic publications might give you useful information. Experts in the field, including suppliers and retailers, are other great resources. They might have found old or obsolete products like your idea, and retired experts might have insights that go especially far back in time.

Also familiarize yourself with some of the common patent search tools. Even if you hire a patent attorney to do your search, a working knowledge of the USPTO's patent search tools will help you do your preliminary research. This knowledge will also help you communicate your goals and findings to anyone you might hire to do your search.

How to Do a Patent Search With the USPTO

You can do patent searches online or in person, for free or for a fee, by yourself or through a patent agent or attorney. Before you decide on your course of action, consider the pros and cons of each search method and the planning required before you begin. Also understand that the most thorough patent searches include:

  • Online research
  • In-person research
  • Expert advice
  • Creativity in deciding where and how to look for prior art

If you do your own patent search, perhaps the best starting point is the USPTO's patent search tool. The Patent Office has granted millions of patents, and its tools allow you to search through records back to 1790. Full-text records are available from 1976 on.

While the USPTO search accepts plain text keywords, there is a standardized system for categorizing patents called the Cooperative Patent Classification (CPC). The CPC is phasing out an earlier system called the United States Patent Classification (USPC). You can search both classification systems at USPTO.gov. The CPC is a set of coded categories that helps you search for certain types of patents. Understanding the CPC is key to a thorough search.

Let's say you invent a better beach chair. To do a basic patent search at USPTO.gov, first find your CPC code:

  • Go to USPTO.gov.
  • In the search bar, type "CPC scheme beach chair" without quotes. (The results are a subset of the USPTO's Classification Schedule, which you can search on CPC code here.)
  • Click the first result, which includes the code A47C.
  • A47C is the CPC class for chairs, sofas, and beds.
  • Scroll down until you find A47C 1/14, "Beach chairs."
  • Compare the given Classification Definition with a description of your invention. If they overlap, you have probably picked a good keyword.
  • Notice the number of dots next to each entry description on the page. The number of dots is a quick way to tell how specific a category is. More specific categories will have more dots. A47C 1/14 has only one dot and is more general.
  • Record the code A47C 1/14.
  • 1/14 is the "subclass."
  • Read the short descriptions that apply to this category: "Chairs for outdoor use, e.g. chairs for relaxation or sun-tanning." These definitions might be more useful keywords.

Armed with this CPC code, you can search for patents:

  • Go to USPTO.gov's Patent Full Text quick search.
  • In the Term 1 field, type "A47C1/14" (no space, no quotes). In Field 1, select Current CPC Classification. Run the search.
  • The tool will return a list of relevant patents from 1976 to the present.
  • Click on the first result.
  • If the patent seems relevant, record the patent number and anything in the patent's citation list that might point you to more prior art.
  • In the menu at the top of the screen, click the Images link.
  • You should now be looking at a full-text copy of the patent.
  • You can save this as a PDF. Be aware that this is a scanned document and the text might not be searchable.
  • Return to the search results.
  • Review all A47C 1/14 patents and decide if they are prior art.

Make detailed records of patents like your invention. Review the most relevant patents in detail, looking for similarities to your invention.

You have just conducted your first patent search! Next, you must find additional relevant CPC codes to comb through more relevant prior art. Once you have looked through all relevant patents, you must search for other prior art in published patent applications. The process is very similar to the patent search:

  • Navigate to USPTO.gov's Patent Application Full Text (AppFT)search.
  • Enter "A47C1/14" (no quotes, no space) in the Term 1 field, and select Current CPC Classification in Field 1. Run the search.
  • Go through the results item by item. The format is similar to the PatFT search, and clicking on the Image link will give you a PDF full-text version of the patent application. Again, some PDFs might not have searchable text.
  • Work your way through this list, noting inventions like yours. This database is only searchable from 2001 on.

Broaden your search if you find few or no related patents. It is likely that you are looking in the wrong place or for the wrong keywords if you find few matches. If you believe your research proves your invention is new, serves a purpose, and is non-obvious, you can go forward with a provisional patent application.

Also consider searching the United States Patent Classification (USPC). The USPC is similar to the CPC, but it is being phased out. You can find a detailed tutorial on using the USPC in the USPTO's 7-Step US Patent Search Strategy Guide.

Keep in mind that a proper patent search can be time consuming. If your idea already exists, then you might find prior art within minutes. But a more complex product might require far more searching and perhaps the help of a professional to search until there is nowhere else to find prior art. Be ready to spend as much time as necessary to find all relevant prior art.

Other online patent search tools are available. Many are free and have tutorials to help novice researchers. Some of the most popular patent search tools are:

  • Google Patents – Google's service is fast, free, and easy to use, but there are fewer search fields, making it harder to narrow your searches. Some of the most recent patents are not yet available. Text-searchable patents go back to 1790, making this tool valuable for finding very old prior art. Some patent searchers report that some existing patents cannot be found in this database.
  • FreePatentsOnline.com – With this service, you can download PDFs of patents and can complement your USPTO searches once you have your CPC code.
  • PatBase – This site has a searchable patent database with patents from many countries and issuing authorities. While a free trial is available, you must buy services.
  • LexisNexis TotalPatent – This pay service is available to law firms, patent professionals, and even some academic institutions.
  • Many more patent search tools.

How to Do a Patent Search at a U.S. Patent and Trademark Resource Center

If patent searching seems intimidating, the U.S. government's Patent and Trademark Depository Library Program offers libraries to help citizens with patent research. These libraries are known as PTRCs (before 2011 known as Patent and Trademark Depository Libraries, or PTDLs), and each state has at least one. Not every PTRC has a complete depository of USPTO records.

To do a patent search at the U.S Patent and Trademark Resource Center:

  • Contact your local PTRC, whose trained staff can help you in your patent search.
  • Ask questions, and make sure your local PTRC offers the services you seek, has convenient hours, and charges fees you are prepared for.
  • If they can help, make an appointment to meet with a PTRC representative.
  • Prepare for this meeting by organizing your research, including a detailed description of your invention, the keywords you have searched for, any relevant prior art you have found, and how you would like the PTRC to help.

The PTRC's search tools are like those at USPTO.gov, but you will have help from people who are experts with these tools. Take advantage of their skills.

Hiring Professionals to Do a Patent Search

If you do not have time to do your own patent search and there are no PTRCs nearby, consider hiring a patent agent or attorney. These professionals are highly qualified experts who make their living researching patents. The USPTO recommends that a novice patent researcher hire a professional for at least some of the patent search process.

Besides patent searching, you can also search for registered patent attorneys and agents at USPTO's Patent Practitioner search. Here, you can find local agents and attorneys, see if they are accepting new clients, and get their contact information. If you find a suitable agent or attorney, research their reputation by checking with the state bar to see if they are still licensed to practice law and still in good standing with the bar.

Another option is to hire a firm that specializes in patent searches. Research any company you consider hiring for a patent search. While many firms are legitimate, many scams exist. Firms that offer to research your patent for less money might be likely to miss important prior art or are scams. Firms that make big promises, such as being able to find all prior art, might consume too much time and bill you for it.

Always ask about fees. You can expect to spend hundreds to thousands of dollars — depending on the job's complexity — on a patent search by a reputable firm. Avoid firms advertising too-good-to-be-true prices, and be ready to shop around.

Taking the Next Step

If you need help doing a patent search, you can post your job on UpCounsel's marketplace. UpCounsel accepts only the top five percent of lawyers. Lawyers on UpCounsel come from law schools such as Harvard Law and Yale Law and average 14 years of legal experience, including work with or on behalf of companies like Google, Stripe, and Twilio.