For patent buyers
Buying a patent is buying a property right, and like real estate, the question that matters most is whether the seller can deliver clean title. Here is the process, start to finish, and the diligence checklist buyers use before they close.
Ten things to verify for every patent before closing. The first two come straight from the USPTO assignment record; the rest need the seller’s disclosures and other public sources.
The seller must be the owner of record. Trace every recorded conveyance from the inventors to the seller, and get an explanation for any inventor without a recorded assignment or any assignor who never received rights.
Any recorded security interest without a matching release means a lender may still have a claim. Require a release, recorded at or before closing.
Licenses are usually not recorded, and a buyer generally takes the patent subject to them. Ask the seller to list every license, covenant not to sue, and standards commitment, and back it with a representation in the agreement.
US maintenance fees are due 3.5, 7.5, and 11.5 years after grant. A missed fee means the patent has expired. Confirm the status and when the next fee is due.
Term generally runs 20 years from the earliest non-provisional US filing date, adjusted by patent term adjustment and cut short by any terminal disclaimer. Calculate it per patent; a portfolio is only worth its remaining life.
Check PTAB for past or pending inter partes reviews, reexaminations, and any litigation where validity was decided. Prior challenges, and the art cited in them, shape what the patent is worth.
Patents from federally funded research carry Bayh-Dole obligations, including a government license. Look for a government interest statement in the patent and a confirmatory license in the assignment record.
If the patent was declared essential to a standard, the FRAND commitment generally follows the patent to the buyer. Check the standards body declaration databases.
If you plan to enforce or keep prosecuting the family, you may need inventor declarations or testimony. Find out whether the inventors are still reachable and still with the seller.
Decide whether you are buying the whole family, including foreign counterparts and pending continuations. Splitting a family between owners can create problems later.
Every other question assumes the seller owns the patent outright. If an inventor never assigned, or a lien was never released, the buyer can end up with less than full title, or with a title problem that surfaces only when the patent is asserted and the defendant questions standing.
You can check a single patent now with the free patent ownership check. For a package, Patencial runs the same check on every patent at once, adds where the inventors are today, and cites every finding to its USPTO reel and frame.
Yes. A patent is property and can be sold to any individual or company. The sale is done with a written assignment, which should be recorded with the USPTO.
Most patent sales go through brokers who market packages from operating companies, universities, and individual inventors. Patents are also sold directly between companies, at auction, and out of bankruptcy proceedings.
Only if the assignment says so. The right to recover damages for infringement that happened before the sale stays with the seller unless it is expressly assigned, so buyers who plan to enforce usually require it in the assignment.
Generally, yes. A buyer takes the patent subject to licenses the seller already granted, and licenses are usually not visible in the public record. That is why the seller should list them and stand behind the list in the purchase agreement.
Yes. Under 35 U.S.C. 261, an assignment not recorded within three months of its date can be void against a later buyer who paid for the patent without notice of it. Recording promptly protects you against the seller selling the same patent twice.
For a single patent, a basic ownership and status review takes hours. For a portfolio, verifying chain of title patent by patent traditionally takes days of paralegal or attorney time. Automated tools such as Patencial reduce the record review to minutes and leave the judgment calls to counsel.
Free patent ownership check
Enter a US patent number to see the owner of record, every recorded assignment, and anything a buyer would want explained.
Read guidePatent chain of title verification
Reconstruct ownership from the named inventors to the current assignee, with every defect cited to a USPTO record.
Read guide35 U.S.C. 261: patent assignments and recording
What Section 261 requires for a valid assignment, and why the three-month recording window decides priority.
Read guidePost-AIA chain of title gaps
How assignee filing under the America Invents Act can leave an inventor assignment unrecorded, and how to find the gap.
Read guidePatent security interests and liens
How a pledged patent shows up in the USPTO record, why an unreleased lien blocks a clean transfer, and what lenders check.
Read guideResearch: what the USPTO record shows for 500 random patents
Unreleased liens, inventors missing from the record, late recordings, and lapsed patents in a random sample of 2020 grants.
Read guidePatent due diligence for M&A
What patent diligence checks before a deal closes, starting with clean ownership of every patent.
Read guideUpload patent numbers. Get a source-cited report in minutes. No credit card required.