Free US Law Dictionary

Patent Pending

The expressions "patent pending" (sometimes abbreviated by "pat. pend." or "pat. pending") or "patent applied for" refer to a warning that inventors are entitled to use in reference to their product or process once a patent application has been filed, but prior to the patent being issued or the application abandoned. The marking serves to notify potential infringers who would copy the invention that they may be liable for damages (including back-dated royalties), seizure, and injunction once a patent is issued.

Fraudulent use of the patent pending warning is prohibited by the law of many countries and inventors should be cautious when marking products or methods that may arguably not be covered by any pending patent application. In some jurisdictions, such as the UK, a warning notice should ideally mention the number of the pending application.[1]