There is no law or rule requiring an inventor to determine whether their invention is patentable before filing a patent application.

Short Answer: It depends upon the developmental stage of the invention, your budget and/or whether you are approaching a critical filing deadline.

It can be quite exciting to develop a new invention that you believe in and want to protect. But if you don't know how to protect your invention, this experience can also be daunting.

Alternative Title: Don't embarrass yourself on Shark Tank by talking about your "provisional patent"!