Q: Do you have to mark the patent number on the product packaging or website?

A: This is covered by Federal law 35 USC 287.

The law limits the patent holder's ability to recover for past patent infringement damages to the first point in time when the infringer was notified about the patent. By contrast, by marking the product, the infringer is legally assumed to have notice as of the time the patent holder first started marking the product.

So this can make a big difference in patent damages. Say an infringer had been infringing your patent for the last three years, but you had never marked your patent product with the patent number. Then you discover the problem and send the infringer a notification letter. The infringer only owes damages from the time of your letter, and not the previous three years.

A: Yes, the owner of the patent can still sue. There is a rule that if a product has a device patent and does not mark the product with the patent number or a web site with the patent numbers, then the owner forfeits damages up to the point that the notice is given (often the filing of the law suit). But the owner can still sue. NOTE -- this rule does not apply to method claims so in some cases an owner has a patent but does not need to mark.

NOTE further, that they do not need to mark the product when the patent is pending.

A: In the United States, marking a product with its patent number is not a legal requirement, but it can be beneficial. If a product is marked with its patent number, it serves as a public notice of the patent, which can enhance your ability to claim damages in a patent infringement case. However, the absence of a patent mark does not prevent a patent owner from filing an infringement lawsuit.

If your product or its packaging does not indicate the patent number, you can still take legal action against infringers. In situations where there is no patent marking, the patent owner must prove that the infringer was aware of the patent and still chose to infringe upon it. This can sometimes make it more challenging to claim damages, especially for the period before the infringer was aware of the patent.

It's also worth noting that virtual patent marking, such as mentioning the patent number on your website, is a recognized method. This can be a practical approach, especially for products where physical marking is difficult.

In your case, if you're considering action for patent infringement, it would be advisable to discuss the specifics of your situation with a legal professional. They can provide guidance tailored to your unique circumstances, including strategies to strengthen your case and potential outcomes.

A: In the U.S., proper marking requires a manufacturer to mark the patented product with the word “Patent” or abbreviation “Pat.” followed by a listing of the applicable patent numbers. The marking should not be concealed, and it should be easy to read.

To virtually mark a product, a patent owner must mark the product itself or to the packaging for the product with the word “patent” or “pat.” followed by an Internet website address. At the listed Internet website address, the patent numbers are listed that apply to the product.