Provisional patent applications: what they protect, and how to draft one that holds up

A US provisional application is the cheapest way to put a date on an invention. It is also easy to get wrong in a way you only discover years later: a provisional protects exactly what it describes, and nothing else.

01What a provisional is

A provisional application (35 U.S.C. 111(b)) is a US filing that gives your invention an early effective filing date for twelve months. It is never examined and never becomes a patent on its own. It needs no claims, no inventor oath and no prior-art disclosure. To keep the date, you must file a regular (nonprovisional) US application, or an international PCT application, that claims the provisional's benefit within twelve months. Limited restoration of a missed deadline exists, but plan on twelve months.

While it is pending you may mark the invention "patent pending". The provisional itself is not published; it becomes public only if a later application that relies on it is published.

02What it actually protects

A later claim gets the provisional's filing date only if the provisional describes that claimed invention in writing and teaches a skilled person how to make and use it (the written-description and enablement requirements of 35 U.S.C. 112(a); see New Railhead Mfg. v. Vermeer Mfg., Fed. Cir. 2002). If the feature that turns out to matter is missing or only gestured at, the early date does not cover it, and anything published in between can be used against you.

The rule of thumb
Write the provisional as if it were the only document a court will ever read about your invention. Breadth of description beats polish.

This is why iPatent puts the detailed description first and ends every draft with a support gaps list: the features, variants and drawings your description mentions but does not yet explain well enough. Closing those gaps is the most valuable thing you can do before filing.

03What to put in it

The problem and context: what existing approaches do and where they fall short.
The parts and how they connect: every component, what it does and what it talks to.
How and why it works: the operating principle, not just the result.
At least one fully worked embodiment: concrete materials, dimensions, values, steps, code paths or parameters.
Alternatives and variants: every substitution you might later want to claim (other materials, ranges, configurations, orders of steps). Unmentioned variants are unprotected.
Drawings: required where they help understanding (35 U.S.C. 113). Describe each figure in the text, with reference numbers.
Data or test results, if you have them, and the uses you foresee.
Claims and an abstract (optional): not required for a provisional, but a draft claim set is a useful checklist of what the description must support.

04Filing it

File through USPTO Patent Center with a cover sheet (form PTO/SB/16, or an application data sheet) naming every inventor, the specification and any drawings, and the fee. Fees in effect since 19 January 2025:

Entity status	Provisional filing fee
Large entity	$325
Small entity	$130
Micro entity (income and filing limits apply)	$65

A size fee applies above 100 sheets. Always confirm against the current USPTO fee schedule before you pay.

05Keep it secret until it is filed

Before you post, pitch or publish
The US gives inventors a one-year grace period for their own disclosures (35 U.S.C. 102(b)(1)). Europe and most other countries do not: under the European Patent Convention (Art. 54) anything made public before your filing date, including your own blog post, talk, preprint or demo, can destroy novelty there.

The same applies to software. Pasting an unfiled invention into a tool that stores, shares or publishes what you type can be a disclosure. The USPTO's 2024 guidance on AI tools warns practitioners about exactly this confidentiality risk. iPatent stores nothing unless you tick "keep a private copy", and never lists or publishes submissions.

06What iPatent does, and what it does not

It drafts. It turns your description into a structured disclosure in patent register, grounded in the structure of a 33,500-segment corpus of the author's own draft disclosures.
It does not search prior art. Its closeness warning compares your text with that corpus only. It is not a novelty or freedom-to-operate opinion.
It is not legal advice. Machine-generated text can be wrong or invent details. Under USPTO rules a person, not a tool, signs and is responsible for every statement filed. Have a registered patent attorney or agent review the draft.
Inventors are people. US law names only natural persons as inventors (Thaler v. Vidal, Fed. Cir. 2022). The invention has to be yours; the tool only helps you write it down.

Draft a disclosure