To ask you to help me with my mortgage maths?

[headscratch]

We are in the very fortunate position at the moment to be able to overpay on our mortgage, and I'm trying to work out the best way to do this. We actually have two mortgages on our house - one currently around £80k that was ported over when we moved from our last property, and another smaller one around £45k that was taken out when we moved house to cover the extra cost.

Both mortgages are currently on the same interest rate. The £80k mortgage is due to finish in 12 years, and the £45k mortgage is due to finish in 25 years.

What I can't figure out is... Does it make any difference which mortgage we overpay? My instinct is to stick any extra cash on the smaller/longer mortgage as we could feasibly pay it off entirely on a few years, and that once that was done we could then put all efforts to clearing the larger/shorter one which of course would be much smaller by then anyway because it only has a 12 year lifespan. But i can't work out the maths of it, maybe it should be the bigger one we tackle first? Or maybe it makes hardly any difference because they are both on the same interest rate? Help!! AIBU to put overpayments towards smaller/longer mortgage?

(Of course, after reading another thread today, we should be just sticking the money in our pension and not on the house... I totally get the sense of that, but... Ooh I just really want to get the mortgage off our backs! It's something I never thought we'd be able to do at this point in our life so I appreciate that I am very lucky indeed to have this as an option.)

I would recommend you use your actual figures and plug them in here

www.moneysavingexpert.com/mortgages/mortgage-overpayment-calculator/

You can then see what the actual saving would b

Hth!

I don't think it matters one way or another mathematically. In your situation I would split it between the 2 sub-accounts. My mortgage company (Halifax) offers mortgage holidays when you have overpaid if you ever need one, and yours might do the same - in which case I believe you would want an overpayment for each mortgage sub-account.

Also, it's not what you asked but you might want to consider putting the money into a pension instead of overpaying. It's the better thing to do for many people, but do ignore this if you have already considered it.

Thanks for the link @OddHoleySocks, I'll check it out.

That's a good point actually @CannotTellIfIABU, if we ever did need a payment holiday, we would be more likely to need one from the bigger mortgage since our minimum payments on that one are bigger.

Is there a limit on the amount you can overpay? For example our mortgage we can only overpay up to 10% per year. If you have more than £4500 which you want to overpay then you would either need to split it or pay off larger one. Also consider which one goes onto SVR first in case your new interest rate is not as high.

@TW2013 no limit on overpayments but they must be monthly, no lump sums allowed. Both mortgages finish at the same time, and probably the SVR would be similar to, if not lower than, what we currently pay.

OK, I have come back to report since I can tell that mumsnet is on the edge of its seat with this one... I fed the numbers through the Martin Lewis overpayment calculator and.... it doesn't make a blind bit of difference where I divert my overpayments to! I still pay back the same amount whether I put it to one mortgage or another, or split it between the two. Therefore as recommended by the pp above I'm going to put it on the larger mortgage so that I build up flexibility for payment holidays. Thank you for the advice!