One of the benefits of a patent under the U.S. system is, for a limited time, the patent owner gets the exclusive right to manufacture, use and sell the invention. The public policy behind this is to create an incentive for creativity and hard work. Of course, that incentive only works if you reward new ideas, so novelty is one of the requirements for obtaining a patent.

Under the patent system, an invention is not “novel” if it was known to the public before the effective filing date of the patent application. Keep in mind that the effective date may be the date of actual filing (for example, a U.S. inventor files an application for a patent in the United States) or a “priority date,” which can be, for example, a date given to an application based on a treaty agreement between the United States and another country (for example, if a Canadian inventor files an application in Canada on June 1, then files a corresponding application in the United States for the same invention on August 1, he or she can claim a priority date of June 1 under a patent treaty between the two countries). Generally, this means that an inventor must be able to keep the invention secret, at least until the application is filed. If the inventor makes a public disclosure of the invention one year before filing a patent application, then the application may be barred from issuing as a patent. In order to trigger that bar, a disclosure must enable a person skilled in the art (meaning someone who understands the field of technology relevant to the invention) to arrive at the invention without exercising inventive skill or undue burden.

So what happens if there’s been a disclosure? In most countries, an enabling disclosure prior to filing means no patent, period. However, a handful of countries are less stringent, allowing a grace period for filing a patent application after a public disclosure by the inventor. The United States is probably the most well-known with its one-year personal grace period, but Australia, Canada, Japan and Mexico, all common filing destinations for U.S. inventors, also allow some grace period between disclosure and filing, though each country has its own particular rules.

For instance, Japan’s grace period is six months, which is shorter than the one-year period recognized by most of the other countries.

Canada’s period is one year, but runs from the filing date in Canada, not the filing date of the priority application. A Patent Cooperation Treaty (PCT) application counts as a Canadian filing date, but filings in other countries do not count as a Canadian filing date. For example, if the disclosure occurred on February 1, 2017, the grace period in Canada would end one year thereafter, and a Canadian or PCT application must be filed prior to February 1, 2018. If the Canadian (or PCT) application is filed on March 1, 2018, the disclosure would be prior art against it even if the Canadian application claims priority to a U.S. application filed on April 1, 2017.

Mexico requires a request for a grace period to be filed when the corresponding application is filed. If an applicant attempts to secure a grace period after the application has been filed, the grace period will not be allowed in Mexico.

Australian law requires that a complete patent application must be filed within the 12-month period to avail of the grace period. Accordingly, provisional applications, which are often not complete applications, generally cannot serve as a basis for a priory date within the grace period in Australia.

Loose lips can sink ships. While a public disclosure of an invention by the inventor is not fatal to obtaining patent protection in all countries, careful consideration of each country’s laws is required to ensure that the particularities of those laws are met. Better, in order to secure the fullest extent of patent protection, applicants should prepare and file any patent application before any public disclosure or commercial use of the invention.