Offset calculator

Get a better understanding of the potential savings that your client could make by offsetting their savings against their mortgage

To tailor the results to your client's circumstances move the sliders below.


With an Offset account, mortgage interest is only calculated on the difference between the two balances.

This calculator is for illustrative purposes only based on interest being applied monthly. Please note some of our mortgages calculate interest daily, the way we calculate interest on the loan balance is set out in the mortgage offer.

The calculations used in the demonstrator assume the following:

  • The interest rate will remain the same throughout the term of the mortgage - our actual mortgage rates available are dependent on market conditions so change from time to time.
  • Requires a static (i.e. fixed) payment to be set up and maintained throughout the mortgage term.

  • The mortgage repayment method is capital and interest.

  • No interest is payable on the Offset savings balance.

  • Regular monthly savings deposits are made throughout the mortgage term (in line with the 'Monthly Savings Deposit' entered), or a constant savings balance is maintained (in line with the 'Current Savings Balance' entered).

  • You make a lump sum deposit into your linked Offset savings account of the amount specified above and that you maintain this balance.

  • The example used on this page assumes that basic and higher rate tax payers do not pay tax on their savings and that additional rate taxpayers pay 45% tax on savings interest and are based on current HM Revenue and Customs rules which are subject to change. Customer usage of any applicable Personal Savings Allowance is not included within these calculations.

  • *AER stands for Annual Equivalent Rate and shows you what the interest rate would be if interest was paid and added each year. This will enable you to compare more easily the return you can expect from your savings over time.

  • Fee calculations are not included within the offset calculator and must be taken into account separately

For more information on Offset payment options please refer to our offset option guide.