United States patent practice includes an option to file a less formal placeholder application called a provisional patent application. A subsequent non-provisional application filed within a year of the provisional application may claim the benefit of the filing date of the earlier filed provisional application.
There is a lot of confusion about the level of detail required for an effective provisional application. The truth is that a provisional application needs to contain far more than an abstract written on the back of an envelope. A provisional application should have a disclosure with ALL of the substantive detail of a non-provisional application. The only real cost savings should be in the level of formality and the omission of redundant sections such as the brief description of the drawings. The formal set of claims may be omitted as they should be redundant with the substance of the disclosure.
Ideally a rough set of claims is prepared even if not included in the provisional application. Preparing claims helps provide a check list for the sufficiency of the disclosure as the contents of the provisional application needs to support the desired claims.
A provisional application that lacks all the detail to make and use an invention may give a false sense of security to a company that filed the deficient provisional application. Provisional applications that only describe one embodiment (and not other viable if suboptimal options) may not adequately protect the innovation. An incomplete provisional application may later hurt the company when reliance on the deficient provisional will not support meaningful patent claims in the non-provisional application.
There can be some cost savings when existing documents are harvested for content and photographs are used instead of formal drawings. Cost “savings” is often a misnomer as it is really a cost deferment if you eventually file a non-provisional application. A non-provisional patent application will need all the pieces, polish, and formality that are sometimes left out of a provisional patent application.
Provisional applications can be a true cost savings, but only when the invention in the provisional application is not carried through to a non-provisional application. Thus, a company seeking more time to decide whether to spend the money to prepare the more formal non-provisional application may file a provisional application before activities that would impact the ability to obtain patent claims such as a public sale, public use, or a public disclosure.
Well-funded clients may choose to create a non-provisional quality patent application, complete with a full set of claims, and file this application initially as a provisional application in order to shift out the expiration date of patent rights.