There are 3 key reasons to incorporate apart from incorporation being a key criteria of IT clients. Incorporating is done for whenever you work on a contract full time or part time but is not necessary if you are looking for a permanent full-time work.

Pay Less Taxes
Your accountant can show you many more key advantages to becoming incorporated.

With your own corporation, you can hire your spouse to work for you, effectively splitting your income.  You can have your company buy computer equipment, or pay for learning, as you see fit to keep up your professional skills. 

It’s Easy
Getting incorporated can be done quite quickly and inexpensively by most lawyers and even online.