Mortgage Overpayment Calculator | NatWest

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Mortgage overpayment calculator 

Our simple calculator will show you whether you could repay your mortgage faster, or reduce the amount you pay each month, by making either regular monthly overpayments or a larger lump sum overpayment.

You can either fill the calculator out manually, or for a more personalised (and potentially more accurate) result, you can log in, and we'll automatically complete the information for you. 

You can find further information on making overpayments below the calculator. If you would prefer to chat to someone about your overpayment options, please contact us on: 0345 30 20 190, Minicom number 0800 917 0526. Lines are open Monday to Friday 8am - 8pm, Saturday 9am - 4pm (excluding public holidays). Calls may be recorded.

What is a regular monthly overpayment?

  • This is an additional payment made on top of your usual monthly payment 
  • This overpayment is flexible and you can choose to make it, or not make it, at any time you want. However, you must still continue to make your normal mortgage payment in full each month.
  • A monthly overpayment will reduce the amount you owe us, which could help you to pay less each month

What is a lump sum overpayment?

  • These are additional payments that you can make at any time and are not linked to your monthly payment. These payments will reduce the balance of your mortgage, which could help you to pay less each month
  • If you make a lump sum overpayment, we may recalculate your contractual monthly payment to reflect the lower balance. If we do reduce your monthly payments, the term of your mortgage will stay the same and you will pay off your mortgage in the same amount of time.
  • If you would like to pay off your mortgage sooner than planned, please contact us on 0345 30 20 190, Minicom number 0800 917 0526, Open Monday to Friday 8am - 8pm, Saturday 9am - 4pm (excluding public holidays) - Calls may be recorded.

How much can I overpay on my mortgage?

  • If you are on a fixed or tracker rate product, you can pay up to 10% of your outstanding balance each year without incurring an Early Repayment Charge. If you wish to repay more than this, a charge will be incurred. For further details of any charges you may incur, please refer to our Terms & Conditions and your mortgage Offer Letter.
  • If you are on a Standard Variable Rate of interest, there is no limit to the amount you can overpay and you will not incur a charge for making any overpayment. 

I'm ready to make an overpayment

If you're comfortable with the different types of overpayments and what they mean you can use the calculator below - it will demonstrate how much money you could save.

See how much you could save Our overpayment calculator

To do this, either pay a lump sum and/or increase your monthly payments.

Paying a lump sum is a way to lower your monthly payments.

Calculate Savings

If you would like to view a graph with details of your overpayment illustration then please turn java scripts on or download the latest browser.

Your current monthly repayment is

New monthly payment
Amount saved each month
Potential mortgage reduction
Total amount of interest you could save
Incomplete information To calculate your savings, additional information is required

Pay It Off Earlier - Either Lump sum or Extra monthly payment is required

Reduce Your Monthly Payment - Lump sum payment is required

Overpayments exceeded Current Balance Overpayments exceeded Current Balance

Overpayments exceeded Current Balance

We can’t calculate your savings We can’t calculate your savings

Sorry we are unable to calculate your savings.  Please call us for more information.

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