Inter partes review became available on September 16, 2012, as a procedure to challenge the validity of patent claims based on patents and printed publications.

What is the difference between post grant review and inter partes review?

A Post Grant Review can be filed on the basis that “more likely than not” one or more claims of that patent will be found invalid. Whereas, in case of Inter Partes Review, there must be “reasonable likelihood” that one of the claims of that patent are invalid.

Who can bring inter partes review?

Any person other than the patent owner is eligible to file for a review. You can only file for a review if you find grounds in §§ 102 or 103 or if you find a basis in prior art or patent publications. Every type of patent is eligible for review.