What Is a Provisional Patent Application?

A provisional patent application is a US filing that gives an inventor a filing date and 12 months to file a regular application, but it never becomes a patent on its own.

Category: Legal and IP · Reviewed 11 November 2026 · 2 min read

How it works

A provisional application is filed with the US Patent and Trademark Office (USPTO). It is not examined and is never granted as a patent. It establishes an earlier filing date, and it expires 12 months after filing. To keep the benefit of that date, the inventor must file a regular nonprovisional application within those 12 months and claim priority to the provisional.

The quality of the provisional matters. Only what the document actually describes can later get credit for the earlier date, so a thin or vague provisional may give little protection. The USPTO explains the application types on its website.

Example

For example, a founder files a provisional application in March. The invention can be described as patent pending from that point. The 12 month window runs until the following March. By then the founder must file a nonprovisional application claiming the provisional's date, or the priority benefit is lost. If the founder does nothing, the provisional simply expires and is not published.

Why founders care

A provisional can buy time to test the market, build a prototype or look for funding before committing to the cost of a full application. It does not prevent others from copying the invention, because there is no enforceable patent. Rules outside the US differ, and some countries require filing before any public disclosure, so timing questions deserve a patent professional.

Common mistakes

Believing a provisional is a patent or an examined application.
Missing the 12 month deadline, which cannot generally be extended.
Filing a vague document that does not support later claims.
Leaving out features that were developed during the year.

Frequently asked questions