Overpaying mortgage vs saving then overpaying

[Chewsday]

I am currently overpaying my mortgage by £750 per month and can repay 10% of the remaining balance each year without penalty. Now that savings accounts are offering decent interest again should I look to pay my monthly overpayment into a savings account to make some money on the interest, then pay off a lump sum of the mortgage either every year or so or at the end of the fixed rate period?

I can’t work out how to calculate how much money I would save either way to compare options. 😬

Mortgage balance is £350k over the next 28 years and fixed at 1.09% for the next 4 years.

Anyone know how to work this out?

So....as don't think I can afford to pay my mortgage as a pensioner, I must overpay my mortgage to reduce the term if I want to retire early.

but if you have a larger pension pot as you've paid more into it, theoretically you'll receive a larger pension, enabling you to pay a mortgage as a pensioner and then once the mortgage is finished you'll still have the larger pension

it also depends on how long until the end of your mortgage, mine was £280 when I was 25 years from retirement, which seems a small amount now, but wasn't then iyswim

Most people’s pensions are nowhere near enough to provide a comfy retirement, they will be even less if you still have to pay a mortgage.
These last few years when the typical yearly interest rate was 1-2%, this wasn’t such an issue.
Paying 5% plus interest every year will be painful, especially in retirement.

Agree with this, but first thing is to have six months cash expenses on hand. Then max to the pension, then worry about mortgage.

You cannot gain back a missed opportunity to invest in your pension when young. The time value is lost when it slips by, and a smaller amount invested now is better in the long run than a larger amount when you are older. Believe me, the years between now and pension time are fleeting.