iPatent · ipatent.qnfo.orgGUIDE · UPDATED 2026-10-06

What is a provisional patent application?

A US provisional patent application in plain words: what it secures, what it costs, what it does not do, and when filing one makes sense.

The short answer

A provisional patent application is a short, informal US filing that fixes a filing date for an invention. It is never examined and never becomes a patent by itself. Within twelve months you file a regular (nonprovisional) application, or an international one, that claims its date (35 U.S.C. 111(b), 119(e)).

What it gives you

a filing date for everything the provisional describes, so a later disclosure, sale or competing filing does not count against what it covers (35 U.S.C. 119(e)(1));
the right to describe the invention as "patent pending";
twelve months to test the market, raise money or improve the invention before paying for a full application;
a priority date that a European or international (PCT) application filed within twelve months can claim (Paris Convention, Art. 4; Art. 87 EPC). See how to file one.

What it does not do

It protects only what it describes. A later claim gets the provisional's date only if the provisional describes and enables it (35 U.S.C. 119(e)(1), applying 112(a)). A thin provisional gives a thin date.
It cannot be extended: twelve months after filing it lapses (35 U.S.C. 111(b)(5)).
It does not stop anyone from copying the invention. Only an issued patent can be enforced.
It does not help against a disclosure made before its filing date outside the US grace period (see before you publish).

What it needs

A written description and drawings that let a skilled person make and use the invention, the inventors' names and a cover sheet; claims, an oath and a formal format are not required (35 U.S.C. 111(b); 37 CFR 1.51(c)). The USPTO filing fee is $325, $130 for a small entity and $65 for a micro entity (37 CFR 1.16(d), fee schedule since 19 January 2025). See what a provisional costs.

When filing one makes sense

Before you show the invention publicly, pitch it outside a confidentiality agreement, or offer it for sale, and when you are still improving it or need time to judge whether a full application is worth its cost. iPatent drafts the description, flags which of your claims the description does not yet support, and lets you print it for filing or for a practitioner's review.

Draft a disclosure, free See a real run