As a general rule of thumb, you should expect that any new patent will last for 20 years from its initial filing date. However, not every field of invention is the same, and there are a few different rules and exceptions for different patents. Starting with the rule of thumb, here are a few additional items to keep in mind when you’re looking into the patent process and patent validity:
Provisional patents last for 12 months and they give you the ability to slap a “patent pending” warning onto your product even before you’ve technically filed for one. Provisional patents can give you up to a year of extra patent coverage, although you can switch your provisional filing to a regular one, making the year disappear. Of course, this is such a bad idea that even the USPTO recommends against it. Therefore it would be best to consult with professionals, such as patent service InventHelp, before getting started.
While plant and utility patents last for 20 years, design patents are only good for 15. It used to be 14 years, but that changed as of May 13, 2015.
Some patents aren’t independent but instead supplement another prior patent. When that’s the case, the child patent expires along with the parent patent, regardless of when it was filed. Usually they’re all filed at the same time, however, so the issue rarely comes up.
If the USPTO or another government agency (such as the FDA for drugs) takes an excessively long time in approving an invention for general sale, then the patent office will extend the patent’s term by the number of days the government wasted. This can potentially add full years to a patent’s lifespan.
Utility patents (and only utility patents) are subject to additional maintenance fees at dates which are 3.5, 7.5, and 11.5 years after issue date (and this date may be set years after the filing date). This window opens six months before the due date and closes six months later, but if you miss your grace period you have to pay an additional surcharge fee. If you ever hear anyone talking about “renewing” a US patent, they’re talking about maintenance fees, because once the 20-year term is up the patent has expired and can never take effect again.
Still, it’s possible for a patent to “revive” if it lapsed thanks to a missed maintenance fee payment. By petitioning the USPTO (and paying a petition fee), you can declare that the lapse was unintentional, pay the money you owe, and again be able to use the patent to enforce your intellectual property rights.
Like most other kinds of law, US patent laws can be complex and arcane, but these exceptions and restrictions exist for good reasons. In addition, the laws tend to change over time, and it is advisable to consult with an attorney, such as InventHelp patent attorney if any confusion. So take care that you remain current or else you’ll be in for an unfortunate surprise.