To clarify do either of the Haven or BOI mortgages attract any form of cashback? I'm assuming not so ignoring BOI as it will be more expensive than Haven.
My primary concern is which will have the least remaining principal amount (Mortgage amount 390K)
I'd ask a slightly different question, which of those mortgages is going to cost me less in the way of interest (net of any cashback offers).
You've a mix of fixed terms in there so seems only fair to compare them over 3 years.
Going with PTSB over Haven will cost you €8,150 more in interest over the three years. But the total cashback will be about €9,069.
So purely on those numbers your be better off going with PTSB... But it's not that simple...
Something to consider is that the 2% cashback on the opening balance is doing all the hard work here. The 2% on monthly repayments is not enough to offset the higher rate. So the longer you stay with PTSB the more the higher rate starts to erode that early upfront benefit.
Run the same calculation over a 4 year horizon (i.e., pretending the prevailing PTSB rate that would apply from year 3 to 4 is also 4.15%) and you get a different answer. Going with PTSB will cost you €10,844 in extra interest. The cashback will only offset 9,492 of that i.e., Haven would be cheaper.
Morale of this story: unless you're going to pay off the mortgage (or switch to a cheaper provider) in the short term this cashback is not going to be worth it.
