So this is more of a question on how to protect your intellectual property rather then to have an explanation of what intellectual property means? Stealing source code and claim that it's yours is just as legal as to steal the manuscript of a novel and claim that you wrote it. Copyrights, Trademarks, and Patents are all ways of protecting intellectual properties (even though patents for software program can be possible in most cases it isn't). However I've never heard of anyone paying the copyright registration fee for a VBA application . The easiest solution here would be a license agreement that clearly states how your solution may be used. Even if it might be easy to crack a VBA app, doing so may not be legal.