Fifth requirement: No secret use

An invention must not be commercially used before the priority date, even if that use is not public (i.e. is secret) and would therefore not affect novelty. The reasoning for this restriction is to prevent inventors extending their legal monopoly over the invention by using it in secret for a period of time before they file for a patent. The law is strict that the patent protection only applies for a limited time and should not be unfairly extended in sneaky ways.

Exceptions to this restriction

1. The 12-month grace period applies to secret use in the same way it applies to the novelty requirement. This means that an inventor can safely use their invention in the 12-month period before applying for patent protection, without impacting the validity of their patent application.
2. The patent law states that some acts will not be taken to be ‘secret use’ for the purpose of this requirement. These acts are:
   • use for the purpose of reasonable trial or experiment only;
   • use occurring solely in the course of a confidential disclosure of the invention;
   • use for any purpose other than for trade or commerce (i.e. noncommercial use is okay); and
   • any use of the invention by or on behalf of the Government.