You will be amazed on how thing should be done and how thing actually works. When doing the mortgage, not only the bank need your credit report but other parties also. Sometimes because of how messy the bank input your info (e.g. some stupid bankers thought that your birthday 02/03/2017 is Feb 3rd 2017 where it is actually 2nd Mar 2017 or they mess up with your first name-last name-middle name), they will require your SIN to cross check your credit.
You are not going to do the mortgage on the bank where you open your checking account right? Other bank may offer better rate and they don't have your credit card info.
Believe me, Equifax and TransUnion are the last two you don't want to mess with unless you are loaded with cash. Speaking from a man who has just been through the whole mortgage paradox.
Welcome to North America! Lol