Mortgage Over Payment

zakato

Hi all
I received an mortgage insurance payout last October. There was enough in the pot to cover the whole mortgage remaining balance. At the time, I was still on a fixed rate with an ERP. I phoned Halifax to enquire about the account and I got the detail of the penalties on each of the sub accounts for paying off early. It was more cost effective to wait until the end of April when the fixed term finished and the account switched back to a variable rate.
I am now at this point and I thought I would try and pay off most of the mortgage. I made an initial payment the other day of £20,000. I did this via online banking as I cannot get through to them on the phone to discuss it. 
The question I have is, when I made the £20,000 payment I see this listed on the mortgage summery page as a payment of £20,000. When I go into the sub account page I see a £16581.80 payment listed. I also see that the mortgage amount outstanding on the main summery page is lower than the amount on the sub account page. I am just wondering if anyone can shed any light on this before I spend a lifetime on the phone trying to get through to them.
Thanks for your help.

A_Frayed_Knot

Wonder if you ever managed to get through on the phone.  If not, then

When making an overpayment you have to specify the amounts and which account/sub account it reduces, if not then they proportion it according to the balances, even if one of your sub accounts is on a 0% interest.

Hope this helps, and Well done on clearing your mortgage.