Interest only calculator

How will this impact my mortgage payments?

To find out how making interest only payments will impact your mortgage, please enter your details into our calculator.

You’ll be able to find the information we need on your latest mortgage statement or any letters we’ve sent you. If you have multiple sub-accounts, you’ll need to enter their details individually and add the payment amounts together. What are sub-accounts?If you’ve made any changes to your mortgage, it could be a mix of different interest rates, terms, and balances. These are known as sub-accounts. Each sub-account has its own individual monthly payment, which we add together to make up your total monthly mortgage payment. You’ll be able to find out if you have sub-accounts on your latest mortgage statement or any letters we’ve sent you.

You must have at least six months left on your current mortgage to apply to switch to interest only payments.

If you have an offset mortgage

Any payments shown don’t include offsetting, so should only be used as an indication.

If your interest rate is due to change next month, please use your new rate.

Your monthly payments:

Once your interest only payments have finished, the amount you pay each month will go up.

Your current monthly payment amount:


While making interest only payments, you’ll pay:


After six months of interest only payments, you’ll pay:


Remember to add the details of any sub-accounts individually and add them together to get your total monthly payment.

These figures are for illustrative purposes only.


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  • We use the following assumptions in the calculations:

    • Multiple sub-accounts must be calculated individually.
    • All years are of equal length.
    • Interest is calculated monthly.
    • Estimate of monthly payments are rounded to the nearest pound.
    • There will not be any other changes to your mortgage which would result in a recalculation of your monthly payment.
    • Your interest rate remains unchanged during the 6 months.
    • Payments do not include any offsetting.

You could lose your home if you don’t keep up your mortgage repayments