Sell Patent Rights: Whole Title or Carved by Field of Use

When people set out to sell patent rights, most of them picture one document and one price. Sign the assignment, record it, collect the money. That is one of four possible deals, and it is often the one with the smallest buyer pool. A patent is a bundle of rights, and the bundle can be sold whole, in shares, by territory, or by the field the invention is used in. Each structure finds a different buyer, carries a different legal label, and leaves the seller holding something different afterwards. This guide is the structuring decision, written for a seller. What the bundle contains, the four ways to sell it, which one a corporate buyer will actually pay for, the strings that survive the sale, and the paperwork that makes it stick. ## What you are selling: a bundle of four rights A patent is written in the negative. It does not give you the right to make your invention. It gives you the right to stop others from making, using, selling or importing it, for the life of the patent, in the country that granted it. Those four exclusionary rights are the asset. When a sale agreement says nothing else, it is assumed to transfer all of them. That is where the two legal labels come from. An assignment is a transfer of ownership, and US practice is strict about what counts: the transfer must include the entirety of the bundle of rights attached to the share being transferred. You can sell all of the patent or a share of it, but whatever share you sell carries every right it has. A licence transfers less than the whole bundle, which is why it can be limited by time, by geography or by field of use. The same source makes the line explicit: even an exclusive licence is not an assignment. Think of a building. Selling it outright is an assignment. Selling a half share is a partial assignment, and you now have a co-owner. Letting a tenant run the ground floor is a licence, however exclusive the lease. All of these are ways to sell patent rights. Only two of them change whose name is on the register. ## Four ways to sell patent rights ### Whole title The clean case, and the one every purchase agreement template is written for. The seller conveys all right, title and interest in the patent and its applications, continuations, divisionals, reissues and foreign counterparts, and walks away. One drafting detail tells you how buyers think. A buyer insists the agreement says all right, title and interest, not all of Seller's right, title and interest, because the seller might hold only a partial interest alongside other owners, and the buyer is paying for the whole. If you cannot give that warranty, say so before the term sheet, not after diligence finds it. The clause-level detail, including what the recording office checks and what it does not, is covered in the clause-by-clause reading of an assignment of patent rights agreement. ### A percentage interest The LegalZoom template invites it: the transfer can be the entire interest, a half or quarter interest, or a transfer valid only in a designated area of the country. What the template does not explain is what a fraction creates. A percentage assignment makes the buyer a joint owner, and US law gives joint owners sweeping independence. Absent an agreement to the contrary, each of the joint owners may make, use, offer to sell, or sell the patented invention without the consent of and without accounting to the other owners. A 25 percent co-owner can license the entire patent to your largest competitor and keep the proceeds. Selling half the patent is not selling half the value. It is admitting a second owner with a full set of keys. Percentage sales exist for good reasons, usually a co-development partner or a founder split. Treat them as what they are: a partnership that needs a co-ownership agreement on licensing, enforcement and proceeds. Treat them as a way to raise cash from a stranger and you have sold the whole patent for a fraction of its price. ### A territory Patents are national. A German patent, a US patent and a Japanese patent on the same invention are three separate assets, and each can be sold on its own. Many sellers do exactly that, selling the US rights while retaining the European rights, because the buyer's market is American and theirs is not. Within the United States the statute goes further. A patentee may grant and convey an exclusive right under the patent to the whole or any specified part of the United States, and that conveyance is an assignment, not a licence. In practice a sub-national territorial sale is rare, because buyers operate nationally. A cross-border split by country is common, and it is the carve most often worth considering for a seller with a family in several jurisdictions and a buyer in one. ### A field of use This is the carve the SERP gets wrong. Several pages say you can assign a patent for one field of use. Under US law you cannot. A field-of-use grant moves less than the whole bundle, so it is a licence, exclusive or otherwise, and title stays with you. That is not a problem. It is the point. The seller keeps the register entry and sells exclusivity in one market. The slicing can be fine. The same invention can be licensed exclusively for aerospace, non-exclusively for automotive, and not at all for medical devices, each deal with its own buyer, price and term. A sole licence is the middle ground, exclusive to the licensee but allowing the owner to keep practising the invention itself. Two cautions. First, the label and the substance can disagree. Parties routinely call a licence exclusive when the licensor remains free to grant licences in other regions or markets, and a buyer reading the grant clause will price what it actually gets, not the word at the top. Second, if an exclusive licence hands over all substantial rights, courts treat it as an assignment in disguise, with tax and standing consequences the parties did not intend. ## Which structure a buyer will actually pay for Start from the buyer's motive, because that decides the structure more than your preference does. | Buyer motive | Structure that fits | Why | |---|---|---| | Closing a gap in an operating portfolio | Whole title, or exclusive field in its own market | It wants to own what it practises and stop rivals practising it | | Enforcing against a named infringer | Whole title or an exclusive licence | Standing to sue depends on exclusivity | | Entering one market the seller does not serve | Exclusive field-of-use or country licence | Pays for its lane, not for yours | | Partnering on development | Percentage interest with a co-ownership agreement | Shares upside and control | The enforcement row is the one sellers underestimate. A patent is bought to be asserted or to deter assertion, and an exclusive licensee generally has standing to help enforce the patent against infringers, while a bare non-exclusive licensee usually does not. Nobody pays a premium for a right they cannot enforce. A buyer that will need to sue in your remaining fields will want you in the case or will want the title, and a field split creates a landscape where different parties enforce the same patent in different markets and have to coordinate their legal positions. Two things follow for a seller. A carve finds buyers a whole-title sale cannot, because a company in one industry will pay for exclusivity in that industry long before it pays for a patent covering three others. And every carve you sell reduces what a later whole-title buyer will pay, because that buyer inherits your licensees. Sell the field you will never serve first, and sell the title last. If you are unsure whether to sell at all, start with the one test that decides the best way to sell a patent: whether anyone is practising the claims today. If you grant exclusivity, protect yourself against a licensee that takes the field and does nothing with it. A minimum annual royalty is the standard answer, so that an exclusive licensee cannot sit on the patent without using it. Companies already operating in the invention's space, competitors, suppliers and manufacturers are the natural counterparties for every one of these structures, which is why how approaching a company to buy your patent actually goes is a separate question from which rights to offer it. ## The strings that survive the sale A patent rarely arrives at a sale untouched. Three kinds of string travel with it. Existing licences. They survive. The buyer steps into your shoes as licensor and is bound by every term, and failing to disclose an existing licence is a serious misrepresentation. A patent carrying an exclusive licence in a major field is a different asset from one without, and a buyer will price it that way or walk. Rights you keep. If you still need to practise the invention in your own products, the assignment must say so through a licence-back, negotiated before signing rather than requested after. If you sold one field or one country, you retain the rest and can license it, which is what makes a carve-first strategy work. Contingent money. Price need not be a single wire. Part of the consideration can be a contingent value right or an assertion royalty, paid if the buyer later enforces the patent successfully. It shifts risk to the seller and raises the headline price, and it is only worth accepting from a buyer with a demonstrated enforcement record. ## The paperwork that makes the sale real Three rules, and most disputes trace to one of them being skipped. It must be in writing, and it must be recorded. Under 35 USC 261 an assignment is void against a later good-faith purchaser who pays value without notice unless it is recorded at the USPTO within three months of its date or before the later purchase. The buyer carries most of that risk, but a seller who sold once and watches a second buyer record first is in a lawsuit either way. In a multi-jurisdiction family, recording happens at every office that granted a member, each with its own form and fee. Licences do not travel by default. Under federal common law a non-exclusive patent licence is a personal right and cannot be transferred without the licensor's permission, and in ProteoTech a court held that an exclusive licence limited to a field was non-assignable too. If your buyer of a field-of-use right expects to resell it, or to carry it through an acquisition, the grant clause has to say so. The deliverables are more than the deed. A buyer expects the executed assignment, the complete prosecution files including original grant certificates, a list of counsel in each country, and a schedule of maintenance fees and deadlines falling in the 90 to 180 days after signing, because a missed annuity in the handover window kills the asset. Expect to warrant that you own the patent alone, have not transferred it before, and did not create it while employed by somebody else. The step-by-step run from offer to recordal is in how a patent sale runs from offer to recordal. ## How we structure a rights sale We hold patent rights of our own and broker sales for third parties, so it is fair to describe how we cut them. Rights are sold or licensed carved by industry, territory or field of use, with title kept whole, which is the carve-first logic above applied as a house rule: a buyer pays for the lane it operates in, and the family stays intact for the next lane. For third-party patents, brokerage is success-based, with commission paid by the seller on completion and a minimum fee of EUR 5,000 per completed transaction. No sale means no fee. A carve only prices if the buyer can see the claim being practised in its field, so before any rights reach a buyer they go through a validation gate: physics-grade claim reconstruction, detectability analysis and validity probability, benchmarked at 0.76 percent mean absolute percentage error against real-world outcomes. Detectability is what turns a field-of-use idea into a field-of-use price. One limit, stated plainly. EX IX is not a firm of patent attorneys. The assignment or licence instrument, the recordal and the co-ownership agreement are drafted and filed through independent licensed counsel. We structure the deal and find the buyer. Whether a licence beats a sale for your situation is a separate decision with its own economics, covered in whether to license or sell your patent. ## FAQ Can you sell patent rights for only one country? Yes. Each national patent in a family is a separate asset, so US rights can be sold while European or Asian members are kept. US law also allows an exclusive right in a specified part of the United States to be assigned, though buyers rarely want less than the whole country. Recording is done office by office. Is selling a field-of-use right the same as selling the patent? No. A field-of-use grant moves less than the whole bundle of rights, so under US practice it is a licence even when exclusive. Title stays with the seller, who can license the remaining fields or sell the title later, subject to the licence already granted. What happens to my existing licensees when I sell the patent? Their licences survive the sale. The buyer becomes the licensor and is bound by the terms, including royalty rates and exclusivity. Every licence must be disclosed in diligence, because an undisclosed one is a misrepresentation that can unwind the deal or trigger a warranty claim. Can the buyer resell the rights I sold them? An assignee of whole title or a percentage can resell what it holds. A licensee usually cannot transfer its licence without the licensor's consent, because a patent licence is treated as a personal right, unless the grant clause expressly permits assignment. Should I sign an NDA before discussing a rights sale? The patent itself is public, so the claims need no protection. Your infringement analysis, unpublished prosecution history and the know-how that makes the invention work are not public, and those are what a buyer actually wants to see. Require an NDA before sharing any of them.