Patents are property. Under 35 U.S.C. 261 they have the attributes of personal property and may be sold, assigned, mortgaged or bequeathed like anything else you own.
The market for them is real but narrow, and most owners never reach it. 58.6% of US utility patents granted in 2014 expired before full term — abandoned at a fee deadline rather than sold. How to sell my patent sets out the process most of those owners never learned.
Who actually buys patents
Four distinct buyer types, valuing the same asset for different reasons.
| Buyer | Why they buy | What they pay for | How to reach them |
|---|---|---|---|
| Operating companies | Defensive cover, filling a gap, blocking a competitor | Relevance to their products and roadmap | Directly, via IP counsel |
| Non-practising entities | Licensing and assertion revenue | Clear claims, identifiable infringers, remaining term | Mostly through brokers |
| Defensive aggregators | Removing a threat from the market for members | Whether the patent could be asserted against members | Membership channels |
| IP funds | Return on a portfolio held for monetisation | Enforceability and damages potential | Broker networks |
These are not interchangeable. A patent that is worthless to an operating company — because it covers something they do not make — can be valuable to an assertion entity if somebody else does. A patent an aggregator will pay to neutralise is one their members are exposed to.
Operating companies are usually the best price and the most reachable. A patent reading on their own shipping product is worth more to them than to anybody buying speculatively, and their IP counsel is findable.
The buyer set is small. RPX has roughly 450 member companies, Allied Security Trust around 50, and the active broker network is a few dozen firms. This is not a market you find by listing somewhere and waiting for enquiries.
What determines the price
Is anyone practising the claims? The single largest factor. A patent that reads on a shipping product has enforcement value. One that does not has option value, and option value decays as the term runs down.
How much term remains. A patent with fifteen years left is a different asset from one with four, both in exclusivity and in the maintenance fees the buyer inherits. A buyer is pricing a stream of remaining exclusivity, not a document.
Claim breadth and clarity. Narrow claims are easy to design around. Vague claims are vulnerable at the PTAB, where institution decisions have become markedly less predictable — the institution rate moved from roughly 65% in October 2024 to about 37% by February 2026. Buyers price both risks.
Chain of title. Gaps in the recorded assignment history are a real problem at diligence. An unrecorded transfer somewhere in the chain can stall a deal for weeks while it is cured, and occasionally kills it.
Family completeness. Buyers generally want the family, not one member. A patent offered alone when three continuations sit elsewhere is a harder sale than the set.
Whether a specific buyer needs it. Patent value is not intrinsic. The same patent can be worth very little to the market generally and a great deal to one company with a product in the space and a reason to worry about it.
How a sale is structured
Assignment, not licence. A sale is executed by written assignment transferring all right, title and interest. Under 35 U.S.C. 261 the assignment should be recorded with the USPTO within three months of execution — or before a subsequent purchase — to defeat a later bona fide purchaser.
Recording is ministerial. It does not validate the transfer or confirm the seller had title. It protects the buyer's priority, and failing to record creates a title gap that surfaces at the next sale rather than immediately.
The agreement around the assignment is where the substance sits. The assignment itself is short. The purchase agreement covers:
- Price and payment structure
- Representations about ownership, encumbrances and known validity issues
- Whether the seller retains a licence back to practise the invention
- Treatment of related family members and foreign counterparts
- Indemnities, and their caps
- How any pending or threatened litigation is handled
Maintenance fees transfer with the patent. This matters more than it sounds. A patent approaching its $8,280 third fee is a liability to a holder who will not pay it and an asset to a buyer who will — the obligation itself is part of what is being traded.
Why so few patents get sold
Traditional brokerage does not serve small holders. Reported commissions run 25-35% of proceeds, and most brokers set minimum deal sizes that exclude single patents. A broker earning a percentage of a $40,000 sale cannot justify six months of outreach, and says so.
Timelines outrun deadlines. A brokered sale commonly takes six to eighteen months, most of it buyer-side diligence. A maintenance fee window is six months from opening to close. Owners who start looking for a buyer when the reminder arrives are usually too late.
Owners do not know what they hold. The decision at a fee deadline is made without a valuation far more often than with one, which means patents are abandoned on instinct rather than evidence.
And the upfront-fee firms have poisoned the well. The FTC's enforcement record against invention-promotion companies — including a judgment exceeding $25 million against World Patent Marketing, where the Commission found virtually all customers lost money — has taught individual inventors, with good reason, to distrust anyone who charges before delivering. That caution is correct. It also stops legitimate transactions from happening, because the reflex extends to anyone who makes contact.
The lapse-versus-sale arithmetic
This is the decision most patent owners actually face, and it is usually framed wrongly as "is this patent worth $8,280 to me" rather than "is this patent worth anything to anyone."
| Let it lapse | Sell it | |
|---|---|---|
| Cash received | $0 | Sale proceeds |
| Future maintenance fees | $0 | $0 — buyer inherits them |
| Patent status | Public domain, permanently | Owned by someone who values it |
| Reversible | Rarely, and weakened by intervening rights | No |
| Time required | None | Weeks to months |
| Requires a valuation | No | Yes, to negotiate sensibly |
Both options end your fee obligation. The difference is whether you receive anything for it.
A worked comparison. A small entity facing the third maintenance fee of $3,312 on a patent with four years of term left, covering a technology the owner has moved on from.
| Path | Immediate cash | Fee saved | Net position |
|---|---|---|---|
| Pay the fee | −$3,312 | — | Four years of exclusivity nobody is using |
| Let it lapse | $0 | $3,312 | Nothing |
| Sell for $25,000 | +$25,000 | $3,312 | $25,000 and no obligation |
The lapse and the sale produce the same fee saving. The only difference is the $25,000, and whether anybody bothered to find out it was available.
Listing a patent for sale
Establish what it is worth first. Selling without a valuation means negotiating against a buyer who has one. A patent valuation sets the floor and tells you whether the sale is worth pursuing at all.
Identify buyers by relevance, not by list. The question is which companies ship products that read on the claims, and which of those have shown they buy. That is research — reading competitor product literature, checking their own patent filings, looking at who has bought in the space before.
Prepare the diligence pack before outreach. Chain of title, maintenance fee status, family members, prior licences or encumbrances, and a claim chart if you are asserting relevance to a product. Buyers who ask for these and wait three weeks lose interest.
Know your remaining term and next fee date. A buyer will ask, and a seller who does not know signals that the asset has not been managed — which colours everything else they are told.
Do not over-list. Offering the same patent through several brokers simultaneously, or listing publicly while also approaching buyers directly, tends to produce competing approaches to the same small buyer set and looks disorganised rather than competitive.
Before you list
- Get a valuation — a number you can defend beats a number you hope for.
- Check chain of title and record any unrecorded assignments before a buyer finds them.
- Confirm the next maintenance fee date, because it sets your real deadline.
- Identify who practises the claims, since that is who will pay most.
- Decide whether you need a licence back before you negotiate, not after.
- Assemble the diligence pack in advance of making contact.
- Take tax advice on the structure before agreeing terms, because it materially affects net proceeds.
- Do not pay an upfront fee to anyone promising to market your invention.