I did not write the code yet but have the concept down, how do I patent the concept? It is for mobile apps.
~ Smithtown, NY
Yes, you can apply before you write the source code. It is not necessary to write a software program before applying for a patent. Much like writing source code, the patent application must explain in sufficient detail how to build the software. For example, it must provide sufficient detail to allow a programmer to build the system without undue experimentation.
So, in this sense, you are not patenting the concept. The patent application will go into the necessary specific details to support the patent claims. It may be that the best time to file a software patent is during the development process. Design documentation can be used to support both the patent application process and the development of the source code. Some useful design documentation might include entity-relationship diagrams, UML class diagrams, wireframes, data flow diagrams, etc.
Frequently, the patent will not cover every aspect of the entire software program. It may be that the documentation needed for the patent may be a small subset of the entire design documentation. Also, the patent may include alternate ways of performing the invention that may not be included in the software's source code.