# Inter partes review (IPR)

An administrative proceeding at the PTAB that allows any person to challenge the validity of an already-granted patent based on prior art in patents or printed publications. IPR is significantly faster and cheaper than district court litigation. Roughly 60% of patent claims that reach a final decision in IPR are canceled. Large companies frequently use IPR to challenge startup patents without going to court.

**Full entry:** https://patentbrief.org/glossary/inter-partes-review

**All patent terms:** https://patentbrief.org/glossary

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_Source: PatentBrief — https://patentbrief.org. A plain-English glossary of US patent terms._