Financially, which mortgage would be the best to overpay?

Southernman

I didn't want to post this in the mortgage free wannabee boards because it's not a diary as such (that will come later once i know what i'm doing). Please move if i am mistaken.

I currently have a mortgage on consent to let the details are:

£53k remaining current interest rate 2.53 fixed for another 2.5 years. I currently overpay £300 a month. There is roughly 17.5 years remaining payments £348pm

I am in the process of buying a property in joint names which would be my residential home (husband is selling his home which is in his sole name- we both live there currently).

The new mortgage is £270k (eek i know) 30 year term (i'm 29) with an interest rate of 1.94% and will be fixed for 5 years. Monthly payments are £994.

Whilst on the surface i would have said overpay the higher interest mortgage first but given the remaining balance being reasonably small, would it be more beneficial to throw my overpayment money at the bigger mortgage albiet with a lower interest rate.

The small consent to let mortgage pays for itself (will be changing to BTL once fixed deal ends).

We are also saving seperately for an extension so can only overpay by £300-400 max monthly over both mortgages. We have no credit card/loan debt.

Not sure if it matters but both mortgages are with Natwest.

Thanks for your help

amnblog

A question for your Accountant as you need to look at the net cost of your BTL Mortgage given your our overall tax position.

On the face of it, it looks like the one to overpay.