A patent is a right to stop other people. Specifically, a right granted by a government allowing the owner to exclude others from making, using, offering to sell, selling or importing an invention within that country for a limited period.
It is not a right to practise your own invention. That distinction catches almost everyone the first time they encounter it, and the consequences are real.
What a patent actually gives you
The right to exclude, under 35 U.S.C. 154. Nothing more.
If you invent an improvement to a machine that somebody else patented, you can patent your improvement. You still cannot build it without a licence from them, because your device contains their claimed elements plus yours. They equally cannot use your improvement without a licence from you.
This is why cross-licensing exists. Two companies holding blocking patents over the same product area frequently license each other rather than litigate, because neither can proceed alone.
The consideration is disclosure. The state grants exclusivity in exchange for publishing the invention so that everyone can learn from it and build on it once the term expires. Applications publish eighteen months after the earliest priority date, and granted patents are always public.
Enforcement is private. No government agency polices patents. If someone infringes, the owner sues — or does not. A patent nobody enforces restricts nobody in practice.
The three types
| Utility | Design | Plant | |
|---|---|---|---|
| Protects | How it works | How it looks | A plant variety |
| Covers | Process, machine, manufacture, composition | Ornamental appearance | Asexually reproduced plants |
| Term | 20 years from filing | 15 years from grant | 20 years from filing |
| Maintenance fees | Three | None | None |
| Share of US grants | Vast majority | Meaningful minority | Very small |
| Typical cost | $8,000 - $20,000+ | Low thousands | Varies |
Utility patents are what people mean by "a patent" in almost every context. They cover function — what the invention does and how.
Design patents cover appearance only. A competitor who changes the look while keeping the function does not infringe. They are cheaper, faster to obtain, and require no maintenance fees at all, which makes them substantially cheaper over twenty years.
Both can cover the same product. A phone might have utility patents on its signal processing and design patents on its shape.
What can be patented
The statutory categories under 35 U.S.C. 101 are process, machine, article of manufacture, and composition of matter — or any new and useful improvement to one of these.
Three requirements on top of that:
Novelty (§102). The invention must be new. Anything publicly available before the effective filing date can defeat it — see prior art for what counts, which is broader than most people expect and includes your own public disclosures.
Non-obviousness (§103). It must not have been obvious to a person of ordinary skill in the field, considering the prior art as a whole. This is the requirement that defeats most applications.
Utility (§101). It must be useful. A low bar in practice for most technologies.
What cannot be patented as such: abstract ideas, laws of nature, and natural phenomena. This exclusion is the basis of most subject-matter rejections in software, business methods and diagnostics, and it is where the law has moved most in the last decade.
What patents are not
Not a trademark. Trademarks protect brand identifiers — names, logos, slogans. They can last indefinitely with renewal, and they protect commercial identity rather than technology.
Not a copyright. Copyright protects original creative expression — writing, music, images, source code as written. It arises automatically on creation and lasts far longer than a patent. Two people who independently write the same program do not infringe each other's copyright; two people who independently build the same patented machine do infringe the patent.
| Patent | Trademark | Copyright | |
|---|---|---|---|
| Protects | Inventions | Brand identifiers | Creative expression |
| Arises | On grant | On use or registration | Automatically |
| Term | 15-20 years | Indefinite with renewal | Life plus 70 years, typically |
| Independent creation | Still infringes | Depends on confusion | Does not infringe |
| Registration required | Yes | Not always | No |
Not international. A US patent has no effect anywhere else. Protection in each country requires a patent there, and the costs multiply accordingly.
Not self-enforcing. A patent is a right to sue. Whether that right is worth anything depends on whether anyone is infringing and whether the owner is prepared to act.
What actually happens to patents
Most do not last their full term, and the data on this is unusually clear because maintenance fee payments are public.
| Grant year | Reached full term | Abandoned early |
|---|---|---|
| 2000 | 51.1% | 48.9% |
| 2010 | 43.1% | 56.9% |
| 2014 | 41.4% | 58.6% |
58.6% of patents granted in 2014 were abandoned before reaching twenty years, because an owner reached a maintenance fee deadline and concluded the patent was not worth the payment.
That is not failure. It is the system working as designed — the fee schedule escalates specifically to force that reassessment rather than let patents accumulate indefinitely at trivial cost.
It is also the clearest available answer to how many patents make money. Most are never licensed, never asserted, never sold, and eventually released.
Full figures by grant year are on the Ipiry Patent Survival Curve.
The lifecycle
| Stage | What happens | Typical timing |
|---|---|---|
| Provisional (optional) | Priority date established, not examined | Day 0 |
| Non-provisional filing | Term clock starts | Within 12 months |
| Publication | Application becomes public | 18 months from priority |
| First office action | Examiner's first rejection | ~19.9 months (FY2024) |
| Responses | One or more rounds | 3-6 months each |
| Grant | Patent issues, fee clock starts | ~26.3 months average |
| First maintenance fee | $430 - $2,150 | 3.5 years after grant |
| Second maintenance fee | $808 - $4,040 | 7.5 years after grant |
| Third maintenance fee | $1,656 - $8,280 | 11.5 years after grant |
| Expiry | Public domain | 20 years from filing |
Note the gap between filing and grant. Because the term runs from filing, a patent granted after three years of examination has around seventeen years of enforceable life, not twenty. See how long does a patent last.
Ownership and inventorship
Two separate questions, routinely conflated.
Inventorship is who conceived the invention. It is a legal determination based on who contributed to the conception of at least one claim, and naming the wrong people can render a patent unenforceable.
Ownership is who holds title. Inventors own their inventions initially, but most assign to an employer under an employment agreement.
A patent commonly names three inventors and is owned entirely by a company. See inventorship for who qualifies and why it matters.
Why anyone bothers
To stop competitors. The primary purpose. A patent covering something a competitor needs is a genuine constraint on their roadmap.
To license. A patent covering something others are already doing can generate royalties without any product of your own.
To sell. Patents are personal property under 35 U.S.C. 261 and are bought and sold — see patents for sale.
For investment and acquisition. Patent portfolios are examined during diligence, and their absence in a technical field invites questions.
Defensively. A patent that a competitor might otherwise have obtained is one they cannot use against you.
And sometimes for none of these. Patents filed without a commercial purpose end up in the 58.6%, released at a fee deadline by an owner who was never going to use them.
Before you decide you need one
- Establish what you are protecting — function points to a utility patent, appearance to a design patent.
- File before any public disclosure. Most countries have no grace period at all, and a conference talk can destroy foreign rights immediately.
- Decide which countries matter, because each is a separate cost.
- Understand it is a right to stop others, not permission to build.
- Budget for the full twenty years, not just to grant — see how much does a patent cost.
- Ask whether anyone would practise the invention, because that determines whether the patent is worth anything at all.