First, a few definitions. A provisional application (note, there is no such thing as a “provisional patent” only a “provisional application”) is an application that expires after one year. It is not examined, cannot issue as a patent and cannot be enforced against anyone. A provisional application does serve to obtain a filing date for all of the information disclosed therein. That is, a provisional application is a place holder for a future non-provisional application.
A non-provisional application (sometimes called a “utility application”; however a utility application means that the invention is “useful” – called “industrial applicability in many foreign jurisdictions” – to distinguish it from design and plant applications) is an application that will be examined by the USPTO and can ultimately issue as a patent. Material cannot be added to the non-provisional application once it has been filed (you can file an additional application, if this is the situation you find yourself in, contact me and we can discuss your options).
There are three reasons for choosing a provisional application over a non-provisional application:
1) It is cheaper
This is true, but only in the short term. In the long term filing a provisional application is more expensive. Because the provisional application cannot issue as a patent, the costs of a provisional application is added to the total cost that an applicant will pay for the process if he/she starts with a non-provisional application. I.e., the provisional application delays the cost of the non-provisional application but does not reduce it (in fact, the defrayed cost may be higher as my fees, USPTO fees and/or draftsman’s fees may increase in the interim).
In addition, a provisional application rarely reduces the cost of the actual non-provisional application. The goals, requirements, formatting, etc. in each filing are different, so while the provisional application may help in understanding, it requires modification for filing as a non-provisional application.
2) It allows the applicant to “test the waters”
In particular, the applicant can approach manufacturers, investors, start marketing the invention, etc or can produce a prototype which can be tested for functionality. He/she then has a year to gauge interest before being required to pay the costs for a non-provisional application.
3) It can be filed much quicker
This is generally true. Because the provisional application has fewer formal requirements, the application can often be filed relatively quickly. This allows for a quick filing date if such is required (for example, if a disclosure is about to occur or if the one year grace period is about to end for the “on sale” or “public disclosure” bars). Further, the applicant can often file disclosure documents (e.g., published articles or information disclosure forms) allowing it to be filed more quickly.
If one of these reasons doesn’t apply, then it doesn’t make sense to file a provisional application rather than a non-provisional application. The higher total cost and the longer Examination process just aren’t worth it in most cases.