Patent requirements means two different things, and mixing them up wastes money.
The statutory tests decide whether your invention can be patented at all.
The filing requirements decide whether your application is accepted and gets a filing date.
They fail differently. A missing form is fixable. A missing description is not.
The two sets
| Statutory tests | Filing requirements | |
|---|---|---|
| Decide | Can this be patented? | Is this application complete? |
| Governed by | §§101, 102, 103, 112 | Rules and forms |
| Assessed by | The examiner, substantively | Office of Patent Application Processing |
| Failure means | Rejection | Notice to file missing parts |
| Fixable after filing | Amend within the disclosure | Mostly yes |
| Disclosure itself | Cannot be added to | — |
The four statutory requirements
| Section | Requires | Fails when |
|---|---|---|
| §101 | Eligible subject matter and utility | Abstract idea, natural law, natural phenomenon |
| §102 | Novelty | A single reference discloses everything claimed |
| §103 | Non-obviousness | A skilled person would find it predictable |
| §112 | Written description, enablement, definiteness | Support or clarity inadequate |
§103 rejects more applications than §102. Novelty asks whether anyone did exactly this; obviousness asks whether it would have been a predictable step, which is a much wider net.
§101: eligibility
| Excluded | Examples |
|---|---|
| Abstract ideas | Fundamental economic practices, methods of organising human activity, mental processes |
| Laws of nature | Physical and biological principles |
| Natural phenomena | Naturally occurring substances |
| Mathematical concepts | Formulas as such |
| The Alice test | |
|---|---|
| Step one | Is the claim directed to an exception? |
| Step two | Do the elements add significantly more? |
| Generic computer implementation | Does not add significantly more |
Software and business methods face this hardest. Reciting a processor, server or mobile device to perform an otherwise abstract method is the characteristic failure.
Utility is also a §101 requirement and is a low bar — specific, substantial and credible. It rarely decides anything. See what can be patented.
§102: novelty
| Prior art includes | Regardless of |
|---|---|
| Patents and published applications | Language |
| Products on sale | Whether patented |
| Publications, papers, catalogues | Jurisdiction |
| Public uses and demonstrations | How obscure |
| Your own disclosure | US: 1-year grace period |
Anticipation requires a single reference disclosing every element. Two references together is an obviousness question, not novelty.
Your own prior disclosure counts. The US grace period is one year; most countries have none.
§103: non-obviousness
| Assessed by | Detail |
|---|---|
| Scope and content of the prior art | What existed |
| Differences from the claims | The gap |
| Level of ordinary skill | Who is judging |
| Secondary considerations | Commercial success, long-felt need, failure of others |
Combining known elements predictably is obvious. That is the standard, and it catches inventions that are genuinely new.
Secondary considerations can rebut it — evidence that others tried and failed, or that the market responded strongly, supports non-obviousness.
Definiteness in practice
| Problem | Effect |
|---|---|
| Relative terms without a reference | "substantially", "about" — context-dependent |
| Means-plus-function | Limited to disclosed structures |
| Missing antecedent basis | Indefiniteness |
| Contradictory limitations | Indefiniteness |
"About" and "substantially" are usually acceptable where the specification gives context, and problematic where it does not.
§112: description and claims
| Requirement | Means |
|---|---|
| Written description | You possessed what you claim |
| Enablement | A skilled person could make and use it |
| Definiteness | Claim boundaries are clear |
| Best mode | The best way you knew at filing |
Enablement is a writing requirement, not a building one. No prototype is needed.
Definiteness is where means-plus-function language causes trouble, because such claims are limited to disclosed structures and their equivalents.
The filing requirements
| Required | Detail |
|---|---|
| Specification | Description of the invention |
| At least one claim | Non-provisional only |
| Drawings | Where necessary to understand |
| Application Data Sheet | Inventors, priority, correspondence |
| Inventor declaration | Statements by each inventor |
| Fees | Filing, search, examination |
| Entity certification | If claiming reduced fees |
| Information Disclosure Statement | Duty of candour |
A provisional needs no claims. That is one of the few structural differences and it is why provisionals are cheaper to prepare.
Missing forms produce a notice to file missing parts, correctable with a surcharge. Missing disclosure is not correctable at all.
The disclosure ceiling
| If prior art appears against | You need already described |
|---|---|
| The specific mechanism | An alternative mechanism |
| A stated value | A range with sub-ranges |
| The material | Alternative materials |
| The arrangement | Alternative geometries |
| The whole combination | A narrower embodiment |
Claims can be narrowed within the disclosure and never extended beyond it. Every row above is amendment room that either exists on your filing date or does not.
Double patenting
| Type | Detail |
|---|---|
| Statutory | Same invention claimed twice — not allowed |
| Obviousness-type | Claims obvious over an earlier commonly owned patent |
| Remedy | Terminal disclaimer |
| Effect of the disclaimer | Caps the later patent's term to the earlier one |
| Also requires | Common ownership |
Terminal disclaimers are routine in deep families and they mean the family expires together even where members were filed years apart.
Check the front page for one before calculating any patent's expiry. See patent family.
Inventorship is a requirement too
| Contribution | Inventorship? |
|---|---|
| Conceived a claimed element | Yes |
| Funded the work | No |
| Managed the project | No |
| Built it to instructions | No |
| Ordinary skill applied | No |
Inventorship changes when claims change. An amendment removing the claims one contributor conceived may remove them as an inventor.
Naming people as a courtesy is a real risk, and joint inventors can each license the whole invention absent an agreement. See inventorship.
Fees are a requirement
| Stage | Large | Small (40%) | Micro (20%) |
|---|---|---|---|
| Filing, search, examination | ~$2,000 | ~$800 | ~$400 |
| Issue fee | ~$1,200 | ~$480 | ~$240 |
| Maintenance, lifetime | $14,470 | $5,788 | $2,894 |
| Micro entity requires | |
|---|---|
| Small entity qualification | Under 500 employees, or an individual |
| ≤4 prior US non-provisionals | Provisionals do not count |
| Income below 3× median household | — |
| No assignment to a party over that limit | — |
Status must be true at each payment, not just at filing. See small entity status.
Requirements differ abroad
| Requirement | United States | Elsewhere |
|---|---|---|
| Grace period | 1 year | Usually none |
| Software eligibility | Alice two-step | EPO: technical character |
| Best mode | Required | Generally not |
| Unity of invention | Restriction practice | Unity requirement |
| Post-grant opposition | PGR, 9 months | EPO opposition, 9 months |
The grace period difference costs the most rights. Filing after disclosure preserves US rights and forfeits nearly everything else. See international patent law.
Testing the requirements cheaply
| Requirement | Cheapest test | Cost |
|---|---|---|
| §102 novelty | Free prior art search | $0 |
| §103 obviousness | Read the close references | $0 |
| §101 eligibility | Assess before drafting | $0 |
| §112 enablement | Can you describe it fully? | $0 |
| Filing requirements | Checklist | $0 |
All four can be assessed before spending anything. The free search addresses novelty directly and indicates obviousness by showing how close the art already is.
§101 should be assessed before drafting, not after the first rejection, particularly for software. See when can a service innovation be patented.
Worked example: which requirement bit
Three applications, same filing date.
| App A | App B | App C | |
|---|---|---|---|
| Field | Mechanical | Software | Chemical |
| Rejection received | §103 | §101 | §112 |
| Reason | Two references combined | Method of organising human activity | Genus claimed, one example given |
| Fixable? | Yes — narrowed to a described alternative | Reframe or abandon | Only within the disclosure |
| Outcome | Granted, narrower | Abandoned after 2 rounds | Granted on the example |
App A survived because alternatives were described. The fallback existed on the filing date.
App B failed a test that was assessable for free before drafting. The eligibility problem was visible in the claim structure.
App C claimed more than it supported. Enablement across a broad genus requires more than one worked example.
Utility is a low bar
| Requirement | Detail |
|---|---|
| Under | §101 |
| Must be | Specific, substantial and credible |
| Fails when | No practical use stated, or the asserted use is incredible |
| In practice | Rarely decides anything |
| Historically relevant | Perpetual motion, unsubstantiated therapeutics |
Almost everything with a stated practical purpose satisfies utility. It is worth knowing about and it is not where applications fail.
What happens after the requirements are met
| Ipiry Patent Survival Curve v1.0 | Rate |
|---|---|
| Survive the 3.5-year fee (2022 cohort) | 85.8% |
| Survive the 7.5-year fee (2018 cohort) | 64.6% |
| Reach full term (2014 cohort) | 41.4% |
| Abandoned before full term | 58.6% |
Computed from 27,273,654 USPTO maintenance fee records covering 8,262,336 US utility patents — see the patent survival curve.
Meeting the requirements gets you a patent. Whether it is worth keeping is a separate question the market answers three times.
What the requirements do not include
| Not required | Note |
|---|---|
| A prototype | Enablement is a writing requirement |
| Commercial success | Helps §103, not required |
| A professional drafter | Pro se is permitted |
| Prior art searching by you | Duty is to disclose what you know |
| Foreign filing | Optional |
| Marking | Affects damages, not validity |
You are not obliged to search. The duty of candour is to disclose material art you know about, not to go looking — though searching is overwhelmingly in your interest.
Patent requirements: the checklist
- Distinguish the statutory tests from the filing requirements. They fail differently.
- Assess §101 before drafting, especially for software.
- Run the free prior art search. It tests novelty directly.
- Expect §103 to be the hard one. Predictable combinations are obvious.
- Describe alternatives and ranges. §112 support cannot be added later.
- No prototype is required. Enablement is a writing requirement.
- Name inventors by conception, not by contribution of money or management.
- File the IDS. The duty of candour is enforceable and unforgiving.
- Check entity status before paying anything.
- Remember the disclosure is the ceiling on everything you can ever claim.