Quick answer: Inter partes review (IPR) is one of the most common ways to challenge a software or technology patent, because software patents are frequently attacked on obviousness grounds using prior patents and printed publications, which is exactly what an IPR allows. The Patent Trial and Appeal Board has technically trained judges, a lower burden of proof than court (preponderance of the evidence), and a roughly 18-month timeline. The main limits are that IPR cannot raise subject-matter eligibility arguments under Section 101, which are often central to software disputes, and that filing carries estoppel.
Software and technology patents end up at the PTAB more than almost any other kind. If you are a tech company on either side of a patent dispute, it helps to understand why IPR fits software so well, and where it falls short. Here is how to think about it.
Why IPR is a natural fit for software patents
IPR is limited to challenges based on prior patents and printed publications, arguing that claims are not new or are obvious. Software is a field with an enormous body of exactly that kind of prior art: earlier patents, technical papers, standards documents, manuals, and published code. Many software patents are also vulnerable to obviousness arguments that combine known techniques. That alignment between what IPR allows and how software patents are most often challenged is a big part of why the PTAB sees so many of them.
Technically trained judges
PTAB judges are patent professionals, and many have engineering or computer science backgrounds. For a dispute that turns on how a distributed system works or what a person of ordinary skill in software would have found obvious, that can be an advantage over a generalist jury that has to absorb the technology from scratch. The argument can be pitched at a more technical level, which often suits software cases.
The big limit: Section 101 stays in court
Here is the catch that matters most for software. Many software patents are challenged on the ground that they claim an abstract idea and are therefore ineligible under Section 101. That argument cannot be raised in an IPR at all. IPR is confined to novelty and obviousness over prior art. So if your strongest attack on a software patent is eligibility, the PTAB cannot give it to you, and district court or a different motion is the route. In a lot of software disputes the smart approach uses both: an IPR on the prior-art grounds and a Section 101 challenge in court.
The lower burden helps
As with any IPR, the petitioner only needs to prove unpatentability by a preponderance of the evidence, rather than the clear and convincing standard a court demands. For obviousness arguments that depend on combining references, where reasonable minds can differ, that lower bar can be the difference between winning and losing.
Cost and timing in a fast-moving field
Software products move quickly, and the roughly eighteen-month IPR timeline can be a strategic fit when a patent is hanging over a product line. The current USPTO fees start at $23,750 to request and $28,125 after institution, before attorney and expert costs, which is generally far less than litigating a software patent through trial. Speed and cost are two of the main reasons technology companies reach for IPR.
Prior art is the whole game
Because IPR lives or dies on prior patents and printed publications, the quality of the prior-art search is decisive in software cases. The best references are often not other patents but older technical literature, conference papers, product documentation, or standards. Investing early in a thorough search, including non-patent literature, tends to be the single highest-leverage step in a software IPR.
Do not forget estoppel
A final written decision estops the petitioner from later raising, in court or at the ITC, any ground it raised or reasonably could have raised in the IPR. For a software company that may face the same patent owner again, that trade-off deserves real thought before filing. The companion posts in this series cover the timeline and the IPR-versus-court decision in more detail.
Frequently asked questions
Can you challenge a software patent with an IPR?
Yes, and it is one of the most common ways to do it. IPR is well suited to software patents because they are often challenged on obviousness grounds using prior patents and printed publications, which is exactly what IPR allows.
Can an IPR be used to argue a software patent is an abstract idea?
No. Subject-matter eligibility under Section 101, including the abstract-idea argument central to many software disputes, cannot be raised in an IPR. That challenge has to be made in court or through other procedures.
Why do tech companies prefer the PTAB for software patents?
The judges are technically trained, the burden of proof is lower than in court, the timeline is shorter at about eighteen months, and the cost is typically far less than full litigation. Those factors fit fast-moving software disputes well.
What kind of prior art works best in a software IPR?
Prior patents and printed publications, which for software often means earlier patents plus non-patent literature such as technical papers, standards documents, manuals, and published code. A thorough prior-art search is usually the most important early step.
How much does a software patent IPR cost?
Government fees start at $23,750 to request and $28,125 after institution, plus attorney and expert costs. Total cost is usually a fraction of litigating the same patent through trial, though it still typically runs into six figures.
If a software or technology patent is in your way, or you are defending one, our team has the technical depth these cases demand. Reach out through patentlaw.us to talk through the prior art and the options.
This article is general information, not legal advice, and does not create an attorney-client relationship. Inter partes review rules and PTAB practice change frequently, and recent changes are still evolving, so confirm the current procedures before relying on them.
