A provisional patent application buys you twelve months. That is the whole proposition, and understanding exactly what those twelve months are worth prevents the two failures that make provisionals worthless.
It is never examined. It never becomes a patent. A provisional sits in the USPTO's records for twelve months and then lapses, and its only function is to establish a date.
What it does
| Provisional | Non-provisional | |
|---|---|---|
| Examined | No | Yes |
| Becomes a patent | Never | Yes |
| Duration | 12 months, then lapses | Until grant or abandonment |
| Starts the 20-year term clock | No | Yes |
| Confers patent pending status | Yes | Yes |
| Published | Never | At 18 months from priority |
| Claims required | No | Yes |
| Oath or declaration required | No | Yes |
| Formal drawings required | No | Yes |
| USPTO fee (micro entity) | ~$60 | ~$400 |
Three things it genuinely provides:
A priority date. Under the first-inventor-to-file system, the date of your earliest supporting application determines who prevails against a later filer. That is the substantive benefit.
Twelve months without consuming term. The twenty-year clock runs from the non-provisional filing date, so a year in provisional status costs nothing in enforceable life. This is genuinely valuable and frequently overlooked.
Freedom to disclose. Once filed, you can present at a conference, pitch investors, demonstrate the product or start selling without destroying your own rights — in the US, and generally abroad via Paris Convention priority.
What it does not do
It confers no enforceable rights. You cannot sue anyone for infringing a provisional. There is no patent, and there may never be one.
It does not stop anyone doing anything. A competitor who sees your product marked patent pending faces uncertainty, not a legal constraint.
It is not examined, so nobody at the USPTO reads it, checks it, or tells you whether it is any good. The first assessment of its adequacy happens years later, usually when somebody is trying to invalidate the resulting patent.
It does not extend to what it fails to describe, which is the failure mode that matters most.
The disclosure requirement, and why it decides everything
A provisional provides priority only for what it adequately describes.
Under 35 U.S.C. 119(e), a claim in the later non-provisional gets the provisional's filing date only if the provisional's disclosure supports that claim under section 112 — enabling a skilled person to make and use it, and showing possession of it.
Claims not supported by the provisional get the later, non-provisional date. And that date may be after a competitor's filing, after your own public disclosure, or after prior art that would otherwise have been too late.
This is assessed claim by claim. A single application can have some claims with the provisional's priority and others with the non-provisional's, depending on what the provisional described.
The failure
A provisional has minimal formal requirements — no claims, no oath, no formal drawings. That makes it easy to file and creates the impression that content matters as little as form.
A two-page description filed to establish a date is the classic mistake. It satisfies the USPTO, which does not examine it, and fails the only test that matters when a claim's priority is challenged in litigation or at the PTAB years later.
By then it is unfixable. You cannot add matter to a provisional retrospectively, and the priority date for those claims is simply lost.
What a provisional should contain
A complete written description, at the level of detail you would put in a non-provisional. What the invention is, how it works, how to make it, what the components are, what materials and parameters apply.
Alternatives and variations. Describe different embodiments — alternative materials, alternative arrangements, ranges rather than single values. Claims drafted twelve months later can only reach what was described, and describing one narrow embodiment supports only narrow claims.
Drawings, informal ones are acceptable. Sketches, CAD output, photographs. Formal patent drawings are not required at this stage.
At least one claim, though not required. Drafting a claim forces you to articulate what you think the invention is, and reveals gaps in the description while you can still fill them.
What you are aiming for: could a skilled person in your field build this from the document alone? If they would have to solve significant problems you have not addressed, the description is not sufficient.
What it costs
| Item | Large entity | Small entity | Micro entity |
|---|---|---|---|
| USPTO filing fee | ~$300 | ~$120 | ~$60 |
| Attorney, minimal preparation | $500-$1,500 | ||
| Attorney, properly drafted | $2,500-$5,000 |
The filing fee is trivial. The drafting is not.
The cheap provisional is frequently false economy, because it is the one that fails to support the claims. A properly drafted provisional costs a meaningful fraction of a full application because it contains most of the same content.
What you save is deferral, not total cost. The full application still has to be written within twelve months. What the provisional buys is time — to raise money, test the market, refine the invention, or decide whether to proceed at all.
The twelve-month deadline
Absolute and unextendable. File a non-provisional claiming priority within twelve months or lose the date.
Nothing reminds you. No notice is sent, nothing publishes, and the provisional lapses silently. The only visible change is that any patent pending marking becomes false — see patent pending for the false marking exposure that creates.
Diarise it the day you file, and set the reminder at nine months rather than eleven. Drafting a non-provisional takes weeks, and a deadline discovered with three weeks left produces a rushed application.
If you disclosed publicly relying on the provisional, the lapse is worse than losing a date. Your own disclosure is now unprotected prior art against any later filing, and the US grace period runs from the disclosure rather than from the lapsed provisional.
Multiple provisionals
A common and sensible practice for inventions that develop over time.
| Filing | Date | Discloses |
|---|---|---|
| Provisional 1 | Jan 2025 | Core mechanism |
| Provisional 2 | Jun 2025 | Improved variant, additional embodiment |
| Provisional 3 | Oct 2025 | Manufacturing method |
| Non-provisional | Jan 2026 | Claims covering all three |
The non-provisional must be filed within twelve months of the earliest provisional it claims priority to — January 2026 in this example.
Each claim gets the date of whichever provisional first supported it. Claims to the core mechanism get January 2025; claims to the manufacturing method get October 2025. Priority is assessed element by element, not application by application.
This is why the sequence matters. Filing a provisional when each significant development occurs preserves the earliest possible date for each element, at a few hundred dollars per filing.
A worked timeline
An inventor with a working concept and a conference presentation booked for April.
| Date | Action | Effect |
|---|---|---|
| Feb 2025 | Provisional filed, properly drafted | Priority date secured, patent pending begins |
| Apr 2025 | Conference presentation | Safe — disclosure after filing |
| Jun 2025 | Product refined, second provisional filed | Later improvements covered |
| Sep 2025 | Investor pitch, product demonstrated | Safe |
| Nov 2025 | Non-provisional drafting begins | Nine months from first provisional |
| Feb 2026 | Non-provisional filed | Deadline met. Term clock starts |
| Aug 2027 | Application publishes | 18 months from Feb 2025 priority |
| ~Apr 2028 | First office action | ~26 months from non-provisional |
| ~2029 | Grant, maintenance fee clock starts | ~17 years enforceable |
Note the publication date. Publication occurs eighteen months from the earliest priority — February 2025 — which is only six months after the non-provisional was filed. Claiming an early priority date accelerates publication.
The version that fails
Same inventor, but the provisional is a three-page summary written in an evening.
| Date | Action | Effect |
|---|---|---|
| Feb 2025 | Thin provisional filed | Priority date claimed |
| Apr 2025 | Conference presentation | Believed safe |
| Feb 2026 | Non-provisional filed with detailed claims | Priority claimed to Feb 2025 |
| 2029 | Patent grants | Appears fine |
| 2032 | Patent asserted; defendant challenges priority | |
| Provisional held not to enable claims 1-8 | Those claims get Feb 2026 | |
| April 2025 conference presentation is now prior art | Claims 1-8 invalid |
The inventor's own disclosure destroyed the claims, because the provisional did not support them and the effective date moved to after the presentation.
Nothing signalled the problem for seven years. The provisional was accepted, the patent granted, and the defect surfaced only when someone had reason to look for it.
Provisional or straight to non-provisional?
| File a provisional if | Go straight to non-provisional if |
|---|---|
| You have an imminent disclosure | The invention is settled |
| Funding is uncertain | You want examination to start |
| The invention is still developing | Speed to grant matters |
| You want to test the market first | You have budget now |
| You want to defer cost by 12 months | You want to avoid a second drafting cycle |
The provisional route adds twelve months to grant. For a patent covering a product with a short commercial life, that delay can matter more than the deferral is worth.
It also means drafting twice — once for the provisional and again for the non-provisional. Where the provisional is drafted properly, the second pass is largely refinement rather than new work.
Before you file a provisional
- Write it as if it were the real application, because for priority purposes it is.
- Describe alternatives and ranges, not just one embodiment.
- Include drawings, informal ones are fine.
- Draft at least one claim to test whether the description supports what you think you have.
- Diarise the twelve-month deadline at nine months, not eleven.
- Do not disclose publicly before filing, even though the grace period exists — most countries have none.
- File additional provisionals as the invention develops.
- Diarise the marking removal date in case you decide not to proceed.