A competitor's patent blocks your product. Before you redesign around it or write a licensing check, it is worth asking whether the patent should have issued at all. A US examiner spends roughly nineteen hours on an application across its entire life, searching a corpus of tens of millions of documents. Things get missed, and when the Patent Trial and Appeal Board takes a second look at claims someone is motivated to attack, a substantial share do not survive.

The cost of pursuing that opportunity runs into hundreds of thousands of dollars for the adversarial proceedings, so the decision is a business calculation before it is a legal one.

The Four US Mechanisms

Inter Partes Review (IPR)

The workhorse. Anyone other than the patent owner can petition the PTAB to cancel claims, but only on anticipation or obviousness, and only using patents and printed publications as evidence. You cannot argue unpatentable subject matter, lack of enablement, or bad inventorship in an IPR.

Timing: available nine months after grant. Hard bar: if you have been served with an infringement complaint, you have twelve months from service to file, and missing it closes the door permanently.

The Board decides whether to institute roughly six months after filing, and institutes on something like three-fifths of petitions. A final written decision is then statutorily due within twelve months. All-in cost commonly runs $300,000 to $600,000 including expert declarations, plus about $40,000 in USPTO fees. Of instituted cases reaching decision, at least some claims fall in the majority.

Post-Grant Review (PGR)

Broader grounds, narrower window. A PGR petition may be filed only within nine months of grant, but it can attack on essentially any invalidity theory — eligibility, written description, enablement, indefiniteness, and public-use or on-sale art that is not a printed publication.

Costs run similar to an IPR. PGR is rarely used, mostly because nine months after grant few companies are aware the patent exists — an argument for running the kind of watch described in patent monitoring alerts for new filings in your field.

Ex Parte Reexamination

The budget option, and the one most small companies should look at first. Anyone may request that the USPTO reexamine a patent based on prior art raising a substantial new question of patentability. Government fees run a few thousand dollars for a small entity and attorney preparation $10,000 to $30,000 — an order of magnitude below an IPR.

The catch is in the name. Ex parte means you file the request and then you are out of it. The patent owner and the examiner conduct the rest of the proceeding; you cannot respond to the owner's arguments or amendments. The owner will usually narrow the claims rather than lose them, and narrowed claims that no longer cover your product are frequently a good enough outcome. Timelines run one to three years, and requests can be filed anonymously through counsel.

Third-Party Preissuance Submission

The cheapest intervention that exists, and almost nobody uses it. While an application is pending, any third party may submit prior art with a concise statement of relevance into the examiner's file. The fee is nominal — free for the first three documents in many cases.

The window is tight: before the earlier of a notice of allowance, or the later of six months after publication and the first rejection. You cannot argue, only supply documents and a short statement of relevance. But putting the killer reference in front of the examiner before allowance prevents a problem for one percent of what solving it later costs. Applications publish eighteen months after priority, as described in when a patent application publishes and what that exposes, and that publication is your notice to act.

Building the Invalidity Case

Every one of these proceedings lives or dies on prior art the examiner did not consider. That means an invalidity search, a deeper exercise than a patentability search: you hunt for a single document, or a combination of two, disclosing every element of a specific claim before a specific date. Searchers routinely spend 40 to 100 hours sweeping foreign patent literature, standards documents, conference proceedings, product manuals, and archived websites. The general method is in how to do a prior art search, applied with a fixed target rather than an open question.

The work product is a claim chart: every claim element on the left, the specific prior-art passage meeting it on the right. An empty cell means the reference does not anticipate, and you are into an obviousness combination, which requires a reason a skilled person would have combined the references — the standard in non-obviousness in patents. Reading claims precisely is the whole game; patent claims explained is the prerequisite.

The Cheaper Alternatives You Should Price First

  • Check whether the patent is even alive. Maintenance fees lapse constantly. A five-minute check on fee status, covered in how to check if a patent is still in force, has ended more than one panic.
  • Read the claims narrowly. A patent's scope is its independent claims, not its title. Many products that "clearly infringe" turn out to miss one required element.
  • Design around it. Usually a fraction of the cost of an IPR, and it produces a product rather than a legal outcome. Start with designing around a patent.
  • License it. A running royalty of three to six percent on a component-level patent is frequently cheaper than the litigation that establishes you did not need one.

The Risks of Attacking

Estoppel is the big one. After a final written decision in an IPR or PGR, the petitioner cannot later raise in court any ground it raised or reasonably could have raised. You get one shot, and if you lose, the patent emerges stronger and your defenses narrower.

Filing also announces you. An owner who did not know your product existed now has your name on a petition. And amendments during reexamination can produce claims that cover your product better than the originals did. If a demand letter started this, work through what to do when a cease and desist letter lands before you commit to a counterattack.

Making the Decision on Engineering Grounds

The fastest resolution is usually technical, not legal: a claim chart against your actual design shows either that you are clear or exactly which element to change. Projects House performs that analysis alongside the engineering, so the answer arrives as a design option rather than a legal bill. Send the patent number and your product description through our contact form.