Mortgage overpayment help

[Namechange6578]

Hi, I am hoping someone can help explain this to me. I can't get my head round it, but prob missing something obvious!...

We have started over paying on our mortgage by £300 a month. Using the banks online overpayment calculator, this shows that it will reduce the mortgage term by 3 years.

When I increase this to £600 per month on the calculator, it then says the term will reduce by 4 yrs 7 months.

Why wouldn't it reduce by a further 3 years if we are paying 2 x £300? I admit im probably not understanding how it works 😂

(to add, we are well within our overpayment limit. Interest rate is 2.79%)

Don't overpay on that interest rate, save the money instead and pay it off at the end of the fixed period.

Then you won't have to worry about the answer to your question, which is generally a moving target anyway, because if you're overpaying, you generally just keep sending extra money, or not, for now, in this case, until the mortgage is gone. It's rare that anyone sticks to exactly £300 extra pm anyway, as in future, you'll likely have more or less disposable income, so will adjust accordingly.

I'll look into savings instead, good idea. We've been overpaying by £150 pm for a few years now, it's the same each month as we have an auto payment set up.

You've only doubled the overpayment, not the total payment.

Agree with PP that you would be better off not overpaying and putting the money into high interest savings. There is a calculator on the MSE website that will tell you how much you'd gain from this.