Patent Law FAQ

What is the ‘infringement test’ for dependent claims in patent applications?

The ‘infringement test’ is a crucial concept in determining the proper dependency of claims in patent applications. As described in MPEP 608.01(n):

‘One test for a proper dependent claim is that the dependent claim must be narrower than the claim(s) from which it depends. In other words, if a dependent claim does not further limit the scope of the claim(s) from which it depends, it is not a proper dependent claim.’

The infringement test states that:

• Any subject matter that would infringe the independent claim must also infringe the dependent claim.
• If it’s possible to infringe the independent claim without infringing the dependent claim, the dependent claim is improper.

This test ensures that dependent claims properly narrow the scope of the claims they depend from, maintaining the hierarchical structure of patent claims.

To learn more:

• infringement test
• dependent claims
• patent application