A provisional patent serves as a low cost "placeholder" for up to 12 months before you file a full patent. It costs less than a patent because it is simpler, excluding legal claims and a costly back-and-forth rejection, rewording and re-examination process between the patent office and a patent lawyer. A provisional patent locks in the date of your future patent's claim to the date you file your provisional patent, as long as you file your patent within 12 months of filing the provisional.
Make a written description of your invention. There are no official forms for explaining your invention in a provisional patent. Explain your invention by starting with a few lines about the background of the invention. Then add a one to two paragraph summary before continuing to descriptions of the drawings you'll include.
Brainstorm broad ways you can apply your invention. To strengthen your future patent application, broader coverage is better. For example, if you invented a device designed to transport people through thin air from one place to another, you would broaden the description to include animals and inanimate objects.
Include as many drawings as possible, including sub-components. Draw the whole invention from multiple angles, including how it connects to other systems or how users employ it, if applicable. Use circled three-digit numbers with lines pointing to components and then include the name and description of each component in the text of the application. Space out each number by 10 so that you can squeeze in new numbers in case you forget to include components in your first draft. Also group numbers by 100s for each page or major sub-component within a page.
Include accompanying documents. Include a cover sheet identifying the application as a provisional application for patent, the names of all inventors, inventor residences, title of the invention, lawyer information (if applicable), correspondence address and any government agency that has a property interest in the application.
Post your description and the accompanying documents as hard copies when you are within 12 months of filing a patent.
Consult a patent or intellectual property lawyer. While it is possible to write a provisional patent yourself, it is worth a few hours of a legal expert's time to verify you've missed nothing and done it right.
After filing a provisional patent, you have the right to state that your invention is "patent-pending."
Wait to file a provisional patent until you are confident you will file a patent within 12 months. Otherwise your provisional patent will expire.