There are several advantages to filing a provisional application for patent:
Lower cost and faster preliminary process
The provisional application filing fee is much less expensive than a Non-Provisional Patent Application.
In addition, the technical requirements are simplified. This means it takes
you less time and money to prepare and file a Provisional Application.
Establishes an official USPTO filing date
Corresponding Non-Provisional Patent Applications filed within twelve months of the Provisional Application
date have the benefit of "relating back" to the Provisional Application.
This means that, should a dispute arise over invention ownership, the USPTO will accept the earlier provisional application filing date as the official
Filing a Provisional Application can be extremely useful in the extremely competitive race to patent an invention. Now that the US is changing from a "First-to-Invent" system to a "First-to-File" system, your filing date will be the most important determinant of whether you--or someone else who filed first--gets a patent. You'll still want to keep your prototypes, journals, notes, etc., but an early-filed application is now of paramount importance, and a Provisional Application for Patent is the quickest, easiest and cheapest way to accomplish this.
One year to assess the commercial viability of your invention
You can take advantage of the Provisional Application's one-year period of coverage
to evaluate the commercial potential of your invention before committing to a Non-Provisional Patent Application.
Use of the "patent pending" notice
Before the provisional application for patent existed, an inventor had to file a
full patent application to use the "Patent Pending" or "Patent Applied For" label.
Now you can do so after filing a Provisional Application. "Patent Pending"
is a useful deterrent to infringement.
Extending the patent term
A patent lasts for 20 years, measured from the date a full patent application is
filed. By first filing a Provisional Application, which is valid for 12 months, you can effectively receive 21 years of protection, beginning with your provisional filing date
A Provisional Application for Patent does not compromise the confidentiality of your application since Provisional Applications are not published.
Provisional Applications are not reviewed by USPTO examiners unless and until you decide to file a corresponding Non-Provisional Application. This
saves you time and money associated with the application.