How long after the invention is developed do I have to file for a patent?

Frequently Asked Questions about Patents

How long after the invention is developed do I have to file for a patent?

  • You have one year from the earliest date of public display, public use or a sale of the invention in which to file for a patent application in the United States. If you do not file within that year, you have forever lost your right to obtain a patent on that invention in the United States.
  • Most foreign countries do not even allow one year. These countries require “absolute novelty,” meaning you may not do anything to place your invention in the public domain prior to filing a patent application.
  • The United States has reciprocal agreements with most countries in the world which allow you to claim the earlier U.S. filing date to establish priority in that particular country, providing you file the foreign application within one year of the U.S. filing date.
  • If you think that there is a possibility that you, your firm, or whomever buys the rights to the invention will market the invention anywhere outside the United States, do not do anything to risk placing the invention in the public domain until after you have a U.S. patent application on file, and be prepared to file foreign patent applications within one year of the U.S. filing date.

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