Overpaying mortgage - what happens if I pay more than 10%?

Supersonos

Been trying to get in touch with Natwest to ask this, but their wait times are consistently 1hr+ and the online "Manage my Mortgage" is offering no help.

My mortgage is £470k and I want to pay a lump sum.  I can overpay up to 10% per year, but what happens if I accidentally go over that 10% by a few hundred pounds?  I've made a few random overpayments over the last 12 months totalling around £10k but I'm having trouble working out exactly how much.  I'm also not sure when the "year" resets allowing me to pay another 10%.

Plus, my mortgage is made up of two sub-accounts, so can I pay 10% of each sub account into each sub account or can I just stuff 10% of the total amount into either sub account.  So confusing!  

Any help appreciated!

MovingForwards

Have you re-read your mortgage offer and the T&C's which you received with it? This covers what happens eg ERCs payable when going over 10%, when your year runs from / to.

Polly05

Does the website not say about early repayment charges? Maybe where it says about overpaying? 

Exodi

The 'year' would likely reset with your mortgage period - eg one year from when you first took out the mortgage.

If you overpay the 10% then you start paying ERC on the surplus. For my mortgage this is anywhere from 1-5% depending on how far through the 5 year fixed term this is.

Try register for an online account - you can usually access all the paperwork with the details through there. Or just ask natwest for a copy of your mortgage agreement.