There is no such thing as a provisional patent.

What exists is a provisional patent application — a filing, not a granted right. It is never examined, never becomes a patent, and expires automatically after twelve months.

The misnomer causes real damage. People file, believe they hold protection, and find at month thirteen that the priority date is gone and their own public disclosures have become prior art against them.

The word "patent" in the phrase is doing work it should not.

What it is and is not

Provisional application Patent
Examined Never Yes
Becomes enforceable No Yes
Can you sue on it No Yes
Duration 12 months, then expires 20 years from filing
Claims required No Yes
Publishes No Yes
Cost ~$60–$300 in fees $8,000–$20,000 all in
What it gives A priority date A right to exclude

A priority date is the whole product. Everything else about a provisional follows from that.

It is not a cheaper patent. It is a placeholder that costs almost nothing and does almost nothing except hold a date.

What the priority date buys

Benefit Detail
A filing date Anything published after it is not prior art against you
12 months to decide Develop, test the market, raise money
Patent pending status A deterrent and a signal
No term consumed The 20 years run from the non-provisional
Foreign filing anchor Priority for a PCT or national filings

The term point is the strongest structural argument. Because the twenty-year clock starts at the non-provisional filing, a provisional adds up to twelve months of protection for free.

Total protected period can reach 21 years — one on the provisional, twenty on the patent.

What it does not buy

Not included Why
Any enforceable right Nothing to infringe
Examination It is never read by an examiner
A patent Requires a separate non-provisional filing
Protection beyond what it describes Priority extends only as far as enablement
Any automatic conversion Nothing happens unless you act
Publication Provisionals are not published

"Nothing happens unless you act" is the sentence that costs people the most. The USPTO does not send a warning at month eleven.

Priority is only as good as the disclosure

This is the failure that surfaces years later.

Provisional contains Priority supports
A full enabling description with alternatives Broad claims
One embodiment described properly That embodiment
A sketch and a paragraph Very little
A concept, no mechanism Nothing

A claim not enabled by the provisional does not get the provisional's date. It gets the non-provisional date, which may be a year later and after intervening prior art.

The problem is invisible until it matters. Nobody examines the provisional, so the weakness only appears when someone challenges the priority claim during an invalidity fight or diligence.

Which is why a cheap provisional is frequently false economy. See provisional patent application.

The twelve-month cliff

Month What should happen
0 Provisional filed
3 Assess market and technical progress
6 Decide: convert, refile, or let go
9 Instruct drafting of the non-provisional
11 File the non-provisional
12 Provisional expires
13 Priority date gone permanently

There is no grace period and no extension. The window closes exactly twelve months after filing.

Refiling a new provisional does not preserve the original date. It starts a fresh twelve months from a later date, and anything published in between is now prior art against you.

Any public disclosure you made relying on the provisional becomes a problem once the priority lapses, because your own disclosure is prior art outside the US grace period and immediately fatal abroad.

What people think they have

Belief Reality
"I have a provisional patent" You have an application on file
"I'm protected for a year" You have a priority date, not protection
"I can stop copycats" No enforceable right exists
"It'll turn into a patent" Only if you file a non-provisional
"I can safely show it now" Only as far as the provisional describes
"I can add details later" New matter cannot be added

"I can add details later" is the second most expensive misunderstanding. Anything not described in the provisional does not get its date, and material added in the non-provisional carries the later date.

Which is an argument for describing alternatives in the provisional, not just the version you built.

Patent pending

A provisional supports the marking, and that is legitimate.

Marking permitted Yes, while the application is on file
Marking after expiry False marking under §292
What it signals An application exists
What it proves Nothing about merit
Enforceable No

Remove the marking when the provisional expires. Packaging printed in bulk routinely outlives a lapsed provisional, and that is the most common false marking scenario. See patent is pending.

What to include

Element Why
Full enabling description Priority extends only this far
Alternatives — materials, geometries, ranges Cannot be added later
Drawings, even informal Support the description
The problem solved Frames the later §103 argument
Test data if you have it Supports enablement
Claims Not required, but useful discipline

Claims are not required in a provisional and drafting them anyway is a useful test: if you cannot write a claim from your own description, the description is probably not enabling.

Alternatives are the single highest-value inclusion. They cost nothing to write now and are permanently unavailable later.

Worked example: two provisionals

Same invention, filed the same month, drafted differently.

Provisional A — two pages

Content Detail
Description The concept and one drawing
Alternatives None
Parameters and materials None
Cost $60 fee, self-drafted

Provisional B — fourteen pages

Content Detail
Description Full mechanism, step by step
Alternatives Six variants — materials, geometries, ranges
Parameters Stated with ranges
Cost $60 fee + $2,400 drafting

Three years later, during an invalidity challenge

Provisional A Provisional B
Claims asserted 1 broad, 3 dependent 1 broad, 12 dependent
Priority challenged on the broad claim Succeeds — not enabled by A Fails — B enabled it
Effective date of the broad claim Non-provisional date, 11 months later Provisional date
Intervening publication Now prior art Not prior art
Outcome Broad claim invalid Claims survive

The $2,400 difference in drafting decided the case. Provisional A held a date for claims it could not support, which is the same as holding no date at all.

Nobody could have known at the time. The provisional was never examined, so the weakness sat undetected for three years.

Cost compared

Provisional Non-provisional
USPTO fee, large entity ~$300 ~$2,000
USPTO fee, small entity ~$120 ~$800
USPTO fee, micro entity ~$60 ~$400
Preparation, minimal A few hundred
Preparation, properly drafted $1,500–$4,000 $5,000–$15,000
Examined Never Yes
Becomes a patent No Possibly

The fee is not the decision. Sixty dollars against three hundred is irrelevant against preparation costs an order of magnitude larger.

The preparation figure is what determines whether the priority is worth anything. A properly drafted provisional costs a fraction of a non-provisional and supports the claims that follow; a minimal one supports very little. See how much does a patent cost.

When a provisional is the right move

Situation Provisional?
Need a date before a conference or launch Yes
Still developing the invention Yes
Raising money and want patent pending Yes
Testing market demand before committing Yes
Description is not yet enabling Wait — file when it is
Already have everything and the money Consider going straight to non-provisional
Deadline in days, description incomplete File, then improve — but know the limits

Filing an inadequate provisional to beat a deadline is defensible as an emergency measure, provided you understand you are buying a date only for what it actually describes.

Filing one because it feels like progress is not. A placeholder that supports nothing is a receipt, not protection.

Multiple provisionals

Approach Effect
One provisional, one non-provisional Standard
Several provisionals, one non-provisional Each element gets the date of the provisional that enabled it
Refiling a provisional at month 12 New date; original priority lost

Serial provisionals work well for evolving inventions. As the design develops, each new provisional captures the new material, and a single non-provisional at the end claims priority from all of them.

The twelve months runs from the earliest one you rely on, so the schedule is set by the first filing, not the last.

What happens if it expires

Priority date Lost permanently
Application Abandoned automatically
Revival Very limited
Your own disclosures during the year Now prior art against you
Refiling Possible, from a new date
Foreign rights Usually gone if you disclosed

The disclosures are what turn an expiry into a disaster. An inventor who filed a provisional, demonstrated the invention at a trade show in month four, and let the provisional lapse has created prior art against themselves.

Most granted patents do not reach full term either, but that is a decision. A lapsed provisional is usually an oversight. See the patent survival curve.

Provisional patent: the checklist

  1. Stop calling it a provisional patent. It is an application, and the wrong word causes the wrong assumptions.
  2. Understand what you bought — a priority date, nothing more.
  3. Make it enabling. Priority extends only as far as the description supports.
  4. Describe alternatives, not just the version you built. They cannot be added later.
  5. Diarise month six and month nine, not month eleven.
  6. File the non-provisional before twelve months. There is no extension.
  7. Do not rely on refiling. A new provisional starts a new date and loses the old one.
  8. Track every public disclosure you make while relying on it.
  9. Remove patent pending marking if the provisional lapses.
  10. Treat a cheap provisional as an emergency measure, not a strategy. A thin one supports claims it cannot carry.