I am attempting to compare two technologies, one of which is claimed to be covered by a licensed patent. The company says that it does not disclose it's licensed patents.

My understanding is that patents that apply to a specific device must at minimum be posted on the device. But does this not apply to licensed patents? Seems like a pretty big loophole. Is this common practice?

  • What would the loophole be in regard to?
    – George White
    Commented Nov 3, 2020 at 19:25
  • My very basic understanding of a patent is that it is a legal monopoly provided by a government for disclosure of an idea to the public. If companies are permitted to have both a monopoly and hide this information, I would consider that skirting the intention of the system or a loophole.
    – ericnutsch
    Commented Nov 3, 2020 at 19:35
  • No one is hiding the content of a patent, that is an impossibility other then the government classifying it. They are not disclosing whether or not they own the patent or have licensed the patent from the owner. The USPTO publishes the granted patent so the content is available as is the applicant/initial owner. The idea is disclosed to the public. As you say, that is critical.
    – George White
    Commented Nov 3, 2020 at 19:39
  • Any given product could be covered by many patents. The patents are published and searchable. If you find a patent covering the technology you are interested in, you would need to contact the patent owner to discuss licensing terms.
    – Eric S
    Commented Nov 4, 2020 at 15:42

2 Answers 2



There is no requirement for a company to make public what patents they have licensed or even what patents are assigned to them. Marking a product with a patent number is optional and provides some enhanced enforcement options to the benefit of the manufacturer.

There has been discussion that the ownership of patents should be more transparent. The USPTO provides a recordation service where ownership changes can be recorded but it is not a requirement nor does doing it affect the rights of the owner. Of course to bring an infringement lawsuit one would need to establish ownership or exclusive licensing of the patent in question.

Licensing is more fluid and complicated than ownership.


A patent license is a contract between two parties, a licensor who owns a patent right and a licensee who wants to practice what the patent claims. If the licensee is a business, it is possible but would be uncommon to pay for a license without knowing what patents it covers. Contracts with businesses are not usually published, so it would be uncommon for you to know what patents are covered by somebody else's license agreement. When an end-user buys a product or service, it comes with an implied license from the seller for any patents that cover the product or service.

If somebody says that they own a patent that covers a technology, whether it is licensed to others probably shouldn't make much difference to you. If you would like to know what patents are owned by a specific owner ("assignee"), you can do a worldwide search on Google Patents or Espacenet by filtering results for the assignee. Be aware that the spellings of company names are inconsistent, so be sure to search with and without "inc", ", inc", and the names of parent companies or subsidiaries. Theoretically, a patent can be sold without recording a new assignment. however, most sales are publicly recorded, at least for US patents.

If you want to know what technologies are covered by patents, you can use those search engines and enter keywords that are related to the technology.

Different countries have different laws about patent marking. Under US law, 35 U.S. Code § 287 says that a patent owner can only collect money for your infringing activity ("damages") once that have put you on notice of your infringement. That can come from them, for example, sending you a letter or by marking their patent number(s) on the product. Some products are small and implement technologies covered by many patents. For such products, a URL to a web page listing patents covering the product is appropriate notice. However, you can be held liable for any infringmeent of patents that claim a method, even if the patent owner provides no marking.

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