​​Labeling your product with information about patent(s) that cover that product is called “patent marking” and is one way to inform the public about your IP rights. While under U.S. law you aren’t required to mark your products, not doing so may limit the amount of damages you can recover if someone infringes your patent(s).

In particular, if you are successful in an infringement lawsuit, you can recover damages from the infringer for up to six years of infringement prior to the date of the lawsuit—but only if the infringer was actually aware of your patent or if you marked your product. In most cases, these past damages are available because the patent holder marked the product, rather than actual knowledge by an infringer.

If your patent only covers a method, rather than a product, then marking is not required – since there is nothing tangible to mark. This might apply, for example, if the patented invention covers a service that cannot be embodied in something physical. If you aren’t sure whether you can or should mark your product, contact your Fenwick & West patent attorney, who would be happy to discuss the options with you.

And, if you aren’t manufacturing any products or providing any services covered by your patent, that’s okay – you can still recover damages and you aren’t required to mark anything.

How to Mark?

You can mark a product by printing “Patent” or the abbreviation “Pat.” together with either the patent number or a free-to-access web address of a page that associates this product with the patent number. The advantage of providing a web address is that you can update the page to add or remove patents as your portfolio changes without having to change how you mark the product itself.

Sometimes an article cannot be marked—for example, because it relates to something going on inside a computer, or because the product itself is too small. In that case, you can mark the packaging that accompanies the product.

To benefit from the legal provisions related to marking, the marking must be substantial and continuous – that is, you should mark substantially all of the products manufactured, not just some of them; and the marking should be continuous over the life of the product or the patent (whichever is shorter).

A product may only be marked with patents that cover the product. Periodically review your product and active patent estate to make sure the marked product is actually covered by the specific language of your active patent claims and to remove patents that no longer cover the product. Marking a product with inapplicable patents can create liability for false marking [under 35 U.S.C. 292].

Finally, if you license your patent to another entity, you should take reasonable steps to ensure that the licensee is marking any products they sell as well.