In the United States, the filing date is the date on which the United States Patent and Trademark Office (USPTO) receives a patent application that meets the minimum requirements. The filing date is important because it determines the priority date of the application and the start of the patent term.
What is required for a filing date
For a nonprovisional utility application filed on or after December 18, 2013, the only requirement for a filing date is a specification, with or without claims. 35 U.S.C. § 111(a)(4); 37 C.F.R. § 1.53(b). The specification must contain a written description of the invention that is clear and complete enough to enable a person skilled in the art to make and use it. 35 U.S.C. § 112(a).
Claims, the filing fee, the inventor’s oath or declaration and the application data sheet may be filed later, usually with a surcharge. Nothing new can be added to the description or drawings after the filing date, however, so the specification and any drawings must be complete when the application is filed.
What a complete application should include
- Specification. A written description of the invention. 35 U.S.C. § 112(a).
- Claims. One or more claims that particularly point out and distinctly claim the invention. 35 U.S.C. § 112(b).
- Drawings, where necessary. Drawings are required where they are necessary to understand the invention. 35 U.S.C. § 113; 37 C.F.R. § 1.84.
- Filing fees. The basic filing, search and examination fees. 35 U.S.C. § 41.
- Application data sheet and inventor’s oath or declaration. These identify the inventors and the applicant. 37 C.F.R. §§ 1.63 and 1.76. (A provisional application uses a cover sheet instead. 37 C.F.R. § 1.51(c).)
File before you disclose
Ideally, file before any public disclosure of the invention. The United States gives inventors a one-year grace period for their own disclosures (35 U.S.C. § 102(b)(1)), but many other countries require absolute novelty, so an early disclosure can cost you foreign patent rights.