The United States is one of the few nations of the world that patents business methods. In 1988, the US Supreme Court cleared the way for business patents under the clause in U.S. patent law that provides for the patenting of "the process, act or method by which something is made". Since 1988, a great number of business patents have been issued in the US.
Decide whether you should keep your business method as a trade secret rather than as a patented invention. Patents expire 20 years from the date of filing, while trade secrets (the formula for Coca-Cola, for example) can be kept indefinitely. Depending on the nature of your business method, however, it may be impossible to keep its details secret. A trade secret offers no protection if a subsequent inventor independently develops a similar or identical business method.
Draft detailed specifications describing your business method including its methods, processes and results. The details should be comprehensive enough to allow someone else to implement it without referring to outside sources. This document will be the core of your patent application.
Navigate to the patent application database maintained by the U.S. Patent and Trademark Office. Research all patent applications for business methods issued since 1988 and compare them with your specifications to see of any of them are similar to yours (this is known as a "prior art" search). This will take many hours, and if you find a business method that is similar enough, it will be difficult for you to obtain a patent. If there are no similar patent applications, your business method may pass the "novelty" requirement of patentability (although this is not certain, because your method will not be "novel" if anyone else invented it first, even if they did not attempt to patent it.
Draft a legal claim asserting that your business method is "novel" and explain why, referring to your prior art search.
Draft a legal claim asserting that your business method is useful (the second main requirement for patentability), and explaining why. To meet this requirement, your method must perform a particular, practical function. An abstract idea (such as a marketing theory) cannot be patented.
Determine exactly why your business method is "non-obvious" (the third requirement for patentability). Draft a legal claim asserting that your business method meets this requirement, and why. To be non-obvious, your business method must have required a creative leap of the imagination -- in other words, it could not have been an obvious innovation from the point of view of someone knowledgeable of the "state of the art" in your industry.
Download a patent application with the U.S. Patent and Trademark Office. Complete it with the aid of your specifications and legal claims, pay the required filing fee and submit it (parts of it can be filed online).
Modify your patent application as periodically requested by the U.S. Patent and Trademark Office. Your patent probably will be issued within 18-24 months of your original filing date.