Do you overpay on your mortgage?

[Fourbyfour]

If so, by a lot? Is it worth doing or putting into savings instead?
If not, I'm interested to know why not.
We pay the agreed amount only at the moment but wonder if we should overpay somewhat and put slightly less into savings (still putting some into savings of course).
Is even just a £100 extra paid on the mortgage a month worth it?

I overpay £30 a month, it knocks a year off our 16.5 year mortgage.

When the sofa payment finishes in May I'll add it to the mortgage & take another two years off.

We do but only by around £100 pcm. I'd really like to move but house prices arnt rising much here and I don't expect we will get much more than we bought it for in 2013. I'd be happy to sell it for 155k and we bought it for 152k. So we need to get the equity from somewhere to move in the next 5-10 years and 100£ is all we can afford really!

On the contingency question - 3-6 months living expenses is usually suggested but depends on personal circumstances. E.g. If a family only has one earner whose job isn't very secure or income unpredictable then 6 months. However, if you have 2 earners in stable jobs, each earning enough to pay bills and food even if the other one isn't earning etc. then you don't need very much (a few k to cover a boiler replacement or car repair etc).

Here's a mortgage overpayment calculator
www.hsbc.co.uk/1/2/mortgages/overpayment-calculator

On the overpayment question - we currently don't overpay. Our mortgage interest rate is only 1%. We are putting more money into pensions and stocks and shares ISA's - where the money has been earning loads more. When the interest rates go up, we will look to reduce the mortgage.