35 U.S.C. § 111 — Application

(a) In General. (1) Written application: a patent application must be made in writing to the Director, by the inventor, unless another provision of this title allows someone else to do it. (2) Contents: it must include a specification (as section 112 requires), a drawing (as section 113 requires), and an oath or declaration (as section 115 requires). (3) Fee, oath or declaration, and claims: the application must come with the required fee. But the fee, oath or declaration, and claims can be submitted later, within a period the Director sets, if a surcharge is paid. If they aren't submitted in time, the application is treated as abandoned. (4) Filing date: the filing date is the day the Patent Office receives a specification, with or without claims. (b) Provisional Application. (1) Authorization: a provisional application must also be made in writing to the Director, by the inventor, unless another provision allows otherwise. It must include a specification (under section 112(a)) and a drawing (under section 113). (2) Claim: a provisional application does not need a claim. (3) Fee: the fee can be paid after filing, within a set period and with a surcharge; missing that deadline means the application is abandoned. (4) Filing date: the same rule as above — the date the Patent Office receives the specification. (5) Abandonment: even without a claim, a provisional application can become a regular application under subsection (a) if the applicant timely requests that, as the Director prescribes. If no request is made, the provisional application is automatically abandoned 12 months after filing and cannot be revived after that, subject to section 119(e)(3). (6) Other basis for provisional application: a regular application filed under (a) can instead be treated as a provisional application, under the Director's rules and section 119(e). (7) No right of priority or benefit of earliest filing date: a provisional application cannot claim priority from another application under section 119, 365(a), or 386(a), and cannot give any later U.S. application the benefit of its filing date under section 120, 121, 365(c), or 386(c). (8) Applicable provisions: the regular patent-application rules apply to provisional applications too, except as otherwise provided, and except that provisional applications don't have to meet sections 131 (examination) and 135 (derivation proceedings). (c) Prior Filed Application. Instead of filing a full specification, an applicant can reference a previously filed application — by application number and the intellectual property authority or country where it was filed — and the Director can let that reference count as the specification and drawings for filing-date purposes, under conditions the Director sets, including payment of a surcharge. The applicant must then submit a copy of that earlier application's specification and any drawings within a period the Director sets. If they don't, the application is treated as abandoned. In fact, the application is treated as if it had never been filed, unless (1) it is revived under section 27, and (2) a copy of the earlier specification and drawings is submitted to the Director.