How Long Is a Patent Valid?

A patent gives an inventor the right to prevent anyone from unauthorised selling, marketing or otherwise using his invention or idea for a period of time. This allows the inventor to create, improve or sell his invention without concern that someone else will steal it. Patents do have some limitations.


The three types of patents are design, utility and plant. A patent protects the invention for a number of years prescribed by government regulations. Patents are generally not renewable but may be extended under certain, limited circumstances.

Utility Patent

An inventor may apply for a utility patent if the invention is functional or has a utilitarian purpose. A utility patent grants 20 years of protection, although a couple of years are often required for the application process. The patent holder has the right to market the invention or to assign certain rights to other persons or manufacturers.

Design Patent

A design patent is granted if the creation is one of design rather than function. With a design patent, good from the time of issue, the inventor has total control of the design and has 14 years to bring it to market.

Plant Patent

Those who produce new varieties of asexually reproducing plants may apply for a plant patent, which lasts for 20 years from the time of application.

Maintenance Fees

To keep a patent in force for the full 20 years, holders of plant and utility patents must pay maintenance fees.