You cannot wait until whenever you want to file a patent application. But, at least in the U.S., the grace period can save you in some cases.

U.S. law recognizes that newcomers to patent law don’t always realize their own prior art can work against them. To do this, the law allows a “grace period” for patent application filings after an otherwise novelty-destroying disclosure by the inventor.

Why it matters: Inventions protected by patents have to be novel. This is the fundamental trade of patent law—you’ve invented something, which you publicly disclose, and in exchange you get a limited government-granted monopoly on it.

• One of the bars to getting a patent is novelty.
• Prior art is practically understood as any piece of public knowledge in existence before the date you file your patent application (e.g., product listings on the web, master’s theses in a public university library, prior abandoned patent applications)
• Prior art also includes offers for sale of the invention (even if they’re confidential or secret).
• An invention is novel if there isn’t a single piece of prior art out there that includes every aspect of the invention.

Zoom in: An inventor’s own public disclosures can be prior art. Without a grace period, an inventor offering their product for sale a day before they apply to patent it would destroy novelty.

• To this end, 35 U.S.C. § 102(b)(1) gives a grace period of 12 months to file.
• This is an exception that applies to disclosures by the inventor or by someone who received the material directly or indirectly from the inventor.

Ideally, you want to file patent applications before anything external happens with the invention.

• This includes before any public disclosures like advertising, published research, whitepapers, product announcements, etc.
• This also includes before an offer for sale—even if that offer is confidential (e.g., under an NDA).

But, the law recognizes that this is not always feasible or how it always works. So, U.S. law gives you a year to file after one of these happens. This can help with either intentionally delaying filing or the “oops” moment when you learn the public disclosure rules after the disclosure happens (but before it’s too late altogether).

The big picture: It’s better to avoid having to find out whether the grace period applies. Startups in the U.S. will want to make sure that even a rudimentary invention capture procedure is in place to make decisions as to whether patenting is of interest for the invention before doing something that could forever damage the ability to patent the invention.

• A provisional patent application is a great way to delay the costs (and decisions) associated with filing a full patent application when pressed for time.

International perspective: Not all countries have the same grace period, and some don’t have one at all. For example, China does not have a grace period except under very specific conditions most U.S. startups would never meet. When taking a patent application family that started in the U.S. to another country, understanding these grace periods become really important. Keeping with the China example, if a U.S. inventor files patent application in the U.S. relying on the the grace period after making its first sale as a supplier of the product, that application can’t be duplicated in China.

The bottom line: The U.S. gives a 12-month grace period to make up for intentional or mistaken activities by a startup that would otherwise destroy its ability to get a patent. Caution should be taken for startups with international ambition because a grace period isn’t available in every country.