You cannot patent an idea. That is the first and most important thing to understand, and it is not a technicality.

A patent covers a specific implementation — a method with defined steps, or a device with defined structure, described in enough detail that a skilled person could build it from your description. "A better way to purify water" is not patentable. A particular filtration arrangement, described so someone could make it, might be.

The gap between an idea and a patentable invention is where most people get stuck, and closing it is real work rather than paperwork.

What has to exist before you file

A description that enables the invention. Under 35 U.S.C. 112, the application must teach a person skilled in the field how to make and use the invention without undue experimentation.

Not a prototype. Reduction to practice is not required for filing. A sufficiently detailed written description constitutes constructive reduction to practice, and many patents issue on inventions that were never built at the time of filing.

Specificity is the test. Ask whether an engineer in the relevant field could build it from your description alone. If they would have to solve significant problems you have not addressed, the description is not yet enough.

You have Patentable?
"An app that helps people find parking" No — a result, not a method
"A system that predicts availability using historical occupancy" Closer, still a result
"A method comprising: partitioning sensor data by time window; computing occupancy probability using [specified technique]; ranking by [specified criteria]" Yes, potentially

The eight steps

1. Write it down properly

Before anything else. What the invention is, how it works, what problem it solves, what alternatives exist, and what specifically is different about yours.

Date it and keep it. Under first-inventor-to-file, conception records do not establish priority the way they once did, but they remain useful for inventorship questions and for derivation proceedings.

Describe alternatives too. A description covering only one embodiment supports narrow claims. Describing variations — different materials, different arrangements, different parameter ranges — supports broader ones.

2. Search the prior art

Do this before spending anything substantial, because most inventions have been described before and finding out early is the cheapest possible outcome.

What to search. Patents and published applications, but also journals, conference papers, product manuals, technical websites and standards documents. Non-patent literature is where the damaging references usually hide.

What you are looking for. Anything disclosing every element of what you plan to claim, which defeats novelty, and anything that in combination would make it obvious.

Your own prior disclosure counts. If you have already presented, sold or published, see step 3 immediately.

See prior art for what qualifies and how the searches work.

3. Check the disclosure clock

This is the step that most often turns out to have been missed.

What you did US position Rest of world
Nothing public Clear Clear
Presented at a conference 12-month grace period running Rights likely lost
Sold or offered for sale 12-month grace period running Rights likely lost
Published or posted publicly 12-month grace period running Rights likely lost
Disclosed under NDA Generally fine Generally fine
Kickstarter or crowdfunding 12-month grace period running Rights likely lost

The US grace period under 102(b)(1) gives twelve months from your own disclosure to file.

Most other countries give nothing. A public disclosure before filing destroys novelty immediately in Europe, China, Japan and most other jurisdictions.

The rule is: file first, disclose second. A provisional application costs a few hundred dollars in fees and can be prepared quickly.

4. Decide whether it is worth it

Three questions that matter more than the technical merits.

Would anyone practise it? A patent covering something a competitor wants to build is worth many times its cost. One covering something nobody makes has option value, and option value declines as term runs down.

Can you afford the full life? Not just the $8,000 to $20,000 to grant, but the $2,894 to $14,470 in maintenance fees. See how much does a patent cost.

Would you enforce it? A patent is a right to sue. If you would never litigate and would never sell, the patent constrains nobody.

58.6% of US utility patents granted in 2014 were abandoned before full term, because their owners eventually answered these questions differently than they had at filing. Answering them first is cheaper.

5. Choose provisional or non-provisional

Provisional Non-provisional
Examined No Yes
Becomes a patent Never Yes
Duration 12 months, then lapses Until grant or abandonment
USPTO fee (micro entity) ~$60 ~$400
Starts the 20-year term clock No Yes
Confers patent pending status Yes Yes

A provisional buys twelve months without consuming term, which is its real value. It is useful when funding is uncertain, when you need to disclose something soon, or when the invention is still developing.

It must still enable the invention. A two-page provisional filed to establish a date provides no priority for claims drafted twelve months later, and the failure surfaces years afterwards when someone is trying to invalidate the patent.

A provisional is not a patent and never becomes one. If you do not file a non-provisional within twelve months, it lapses and you have nothing — and any "patent pending" marking has to come off. See patent pending.

6. File the application

What it contains: a specification describing the invention, drawings where they aid understanding, claims defining what you are protecting, an abstract, and an oath or declaration from each inventor.

The claims are the patent. Everything else supports them. A claim set that is easy to design around protects nothing, however good the description.

Name the inventors correctly. Inventorship is a legal determination about who conceived the claimed invention, not who worked on the project. Getting it wrong can render the patent unenforceable — see inventorship.

Claim entity status. Micro entity cuts USPTO fees by 80% and small entity by 60%. The tests are specific and worth checking.

7. Respond to office actions

Most applications are rejected first time. It is the normal course of patent prosecution, not a sign that anything has gone wrong.

You have three months to respond, extendable to six for a fee that also reduces Patent Term Adjustment day for day.

Argue before amending where you can. Every narrowing amendment creates prosecution history estoppel and limits what the doctrine of equivalents can later reach.

Consider an examiner interview. Fifteen minutes on a call frequently establishes what would be allowable, which two more written rounds might not.

See office action for the rejection types and how to respond to each.

8. Pay the issue fee

A notice of allowance means the claims are allowed. The issue fee is due within three months and is not extendable.

The patent grants and the maintenance fee clock starts — 3.5, 7.5 and 11.5 years from that date, not from filing.

What it costs, realistically

A solo inventor, micro entity, straightforward mechanical invention:

Item Cost
Provisional, properly drafted $2,500
Utility application drafting $6,000
USPTO filing fees (micro) $400
One office action response $2,000
Issue fee (micro) $240
Total to grant $11,140
Maintenance fees, all three (micro) $2,894
Total over 20 years $14,034

Software and biotech cost substantially more, largely because subject-matter rejections require multiple rounds.

The scams

This deserves its own section because the industry preys on individual inventors specifically.

Invention promotion companies offer, for an upfront fee, to evaluate your invention and market it to industry. The FTC has taken repeated enforcement action, including a judgment exceeding $25 million against World Patent Marketing, where the Commission found that virtually all customers lost money.

Warning sign What it means
Upfront fee to "evaluate" or "market" your invention The fee is the business model
Unsolicited approach after your application publishes They read the public filing
Enthusiastic assessment before seeing details Nobody can evaluate what they have not read
Promises of licensing deals or royalties No legitimate firm promises outcomes
Pressure to decide quickly Legitimate work does not have deadlines you did not set
Reluctance to disclose success rates Federal law requires disclosure of specific statistics

The American Inventors Protection Act requires invention promoters to disclose how many clients they have had, how many received a net financial profit, and how many entered licence agreements. Ask for those figures in writing. The response tells you what you need to know.

Legitimate patent attorneys and agents charge for work performed — drafting, filing, responding to office actions. They do not charge to evaluate whether your idea is good, and they do not promise commercial outcomes.

Expect unsolicited approaches after publication. Your application publishes eighteen months after filing, becomes public, and promoters harvest the data.

If your idea came from work

Read your employment agreement before filing anything.

Most include a present-tense obligation to assign inventions made within the scope of employment, and many extend to inventions made using company resources or relating to the company's business.

Some states limit these. California Labor Code section 2870 and similar provisions in other states restrict how far an assignment obligation can reach — typically excluding inventions developed entirely on your own time without company resources and unrelated to the company's business.

Filing an application on an invention your employer owns creates a problem rather than an asset, and it is much easier to resolve before filing than after.

Selling instead of patenting

Without a patent or application you have very little to sell. Companies generally will not sign confidentiality agreements for unsolicited submissions, precisely to avoid claims that they took an idea they were already working on.

With at least a filed application, the conversation changes. You have a priority date, something identifiable to transfer, and a basis for a confidentiality discussion.

See how to sell my patent for the process once you have something to sell.

Before you file

  1. Develop the idea into a specific implementation somebody could build.
  2. Search the prior art before spending on drafting.
  3. Check whether you have already disclosed publicly, and act immediately if you have.
  4. Read your employment agreement if the invention relates to your work.
  5. Ask whether anyone would practise it, honestly.
  6. Check micro entity eligibility — it cuts USPTO fees by 80%.
  7. File before any further disclosure, even if only a provisional.
  8. Refuse any upfront fee to evaluate or market the invention.