I recently got approved 3.84% IO fixed for 3 years for 180k Investor loan from CBA (this is the fixed part of a total 320k loan at 80% LVR). I went through a mortgage broker. One of my colleagues said that he has seen better interest rates from CBA. This got me thinking. (Of course, first I asked him if he is talking about IO, if he is talking about 80% LVR etc) 1) What are the factors determining interest rate? I understand that total loan amount and LVR are obvious factors. What else will influence it? Credit score? 2) If I approach the bank directly with the same application (instead of via mortgage broker), will the interest rate offered remain the same? In other words, will the channel through which the application was received by the bank, change the interest rate? 3) Is there any subjective factor in determining the interest rate? Or is it purely numbers based i.e. if 2 people with same income, same loan amount, same LVR etc. apply to the same bank, would they be offered the same interest rate? Thanks in advance for any replies.