Understanding patent time limits, including how long they remain valid and when you should file your application, can help protect your rights to your intellectual property, such as an invention or business method, from being exploited, used, or sold by someone other than you.

What is a Patent?

A patent is a government-issued license or exclusive rights to an invention that prevents other people from using, selling, and claiming it for their use without the permission of the patent owner while the patent is valid. Patents issued in the United States are only valid in the U.S. and its territories.

What Can I Patent?

There are almost no restrictions on what can be patented in the United States. If the invention or item solves a problem or produces an actual result and is man-made, it can be patented. Business methods and software are also some examples of the things that can be patented.

How Do I apply for a Patent?

Filing a patent in the United States requires that the person applying for the patent be the owner or inventor of the item, that the filing of the application is within the time limits specified and that certain conditions be met.

  • Ownership – United States Patent Law requires that the patent applicant be the registered owner or inventor of the item, the inventor's legal representative, or administrator of the inventor's estate. If more than one person is the inventor, then a joint application is to be filed. Employees of the United States Patent Office are prohibited from applying for patents.
  • Time Limits – Patents issued by the U.S. are guided by unique one-year statutory limitations and failure to comply with the following limitations can result in your application being denied:
    • the application must be filed within one year of the date the invention is offered for sale
    • the application must be filed within one year of the date of the invention being discussed or reported on in printed media
  • Conditions – In addition to the time limit, the inventor must also consider the following conditions which can factor into the approval of the patent application:
    • whether other individuals have filed or will file patents for the invention, which can delay approval or cause denial
    • when the other individuals will file — the inventor to file first has the greatest advantage.
    • the exact date the inventor publicly disclosed or discussed and offered for sale or sold the invention. The one-year statutory bar begins the moment the inventor discusses or sells the invention. Failure to keep note of the date can result in denial.

How Long Is a Patent Valid For?

Patents provide protection that lasts only as long as the patent remains valid. In the United States, most patents are valid for up to twenty years from the filing date. To keep the patent valid, owners are required to pay maintenance fees every three and a half years.

The exceptions to the twenty-year rule are those patents filed before June 8, 1995, with the patents remaining valid up to seventeen years from the date the patent was granted.

A simple way to determine the length of time your patent is valid, check the reference number. Patents with the date the permit was granted and the reference number “45” are valid up to seventeen years while patents with the date the patent was filed with the reference number “22”, are valid up to twenty years.

What Happens When My Patent Expires?

Patents expire when the time limit is up, or the patent has been abandoned due to non-payment of the maintenance fees. It is common for many patents to be abandoned before the time limit because of the increase in maintenance fees over the life of the patent.

Once the patent expires or is abandoned, the protection from exploitation wanes. You no longer own the exclusive rights to the invention, and the proprietary information about your invention becomes available to the public. This means other people can create, improve upon, sell, import, distribute, and claim your invention for themselves without your permission.

Are you ready to file your patent application? To make sure you're complying with the specific time limits, you can post your legal need on UpCounsel's marketplace. UpCounsel accepts only the top 5 percent of lawyers to its site. 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, Menlo Ventures, and Airbnb.