Offset calculator

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


With an Offset account, mortgage interest is only calculated on the difference between the two balances.
All offset mortgages effectively work by offsetting the interest usually charged on your client’s mortgage, with interest from a linked offset savings account. However, there are two main ways of putting your client’s savings balance to use with offset:

  • Pay Off Sooner (Static) – your client will keep their repayments roughly the same as they would be without offset, and instead they put the benefits of offset into paying off the mortgage earlier.
  • Reduce Payments Now (Net) - we will utilise your client’s offset savings balance to reduce their monthly payments consistently across the term of their mortgage.
For more information on Offset payment options please refer to our offset option guide

Use our offset mortgage calculator to see how your client’s savings could reduce their monthly payments or they could pay off their mortgage sooner. 

Please note

This calculator is for illustrative purposes only based on interest being applied daily. 
The calculations used in this illustrator are based on the following:

  • The `Pay off sooner (static)` offset mortgage option - in the illustrator the interest rate for this offset mortgage type is based on the offset product rate, Discount Standard Variable Rate and Standard Variable Rate. Example - if a product that you selected is shorter than five years ie. 2-year fixed product, a Discount Standard Variable Rate is applied when the product term comes to an end (in this case after year 2). Discount Standard Variable Rate is applied only until year 5. After that time your payments are recalculated against Standard Variable Rate and that monthly payment is fixed for the rest of the mortgage term. 
  • Reduce payments now (net) ` offset mortgage option - the illustrator calculates payments against the offset product rate for the whole of the mortgage term. We do not apply either Discount Standard Variable Rate or Standard Variable Rate.
  • Discount Standard Variable Rate is only applied when a product with end date less than 5 years is selected. Our actual mortgage rates available are dependent on market conditions so change from time to time.
  • `Pay off sooner (static)` offset mortgage requires a static (i.e. fixed) payment to be set up and maintained throughout the mortgage term in order to pay the mortgage off faster.
  • The mortgage repayment method is capital and interest and interest only.
  • No interest is payable on the Offset savings balance.
  • Customer usage of any applicable Personal Savings Allowance is not included in these calculations.
  • You make a lump sum deposit into your linked Offset savings account of the amount specified above (in the Savings Balance field) and that you maintain this balance.
  • Fee calculations are included within the offset calculator.

The actual amount your client can borrow, term and repayment method available will vary depending upon your client’s personal circumstances and borrowing requirements. Applications subject to standard lending criteria and all loans subject to status. A product fee may apply. Early repayment charges and other fees and charges will apply.

However they choose to manage their Offset Account they will need to select one of the available monthly payment options. If their aim is to Offset in order to pay off their mortgage sooner, they must choose the `Pay Off Sooner` option.

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