Mortgage help for financial fool

youbluebeauty

Hope someone can give a fool like me some help on the best options regarding a mortgage and an ISA. We have been very, very cash strapped for a number of years. We both work 40 hour weeks but we only just keep our heads above water.  We are not very clever with personal finances so any help would be great.
We have only been able have an interest only mortgage policy which costs us £600 per month in repayments. There is around £110000 left on the mortgage. We are charged around £2800 per year interest. So of the £7200 per year repayments, only £4400 goes towards reducing the mortgage.
We have savings of around £50000, and growing, in an ISA that we intended to use as a lump sum to go towards paying off the mortgage when the policy ends - in 10 years.
Should we use this ISA now to reduce the size of the mortgage and the interest charges, or leave it to the end of the term and use it towards clearing the remainder. Apologies if this is wordy or not very clear - it is probably an example of our personal finance incompetence. Thank you.

El_Torro

You say you have an interest only mortgage but you are not only paying interest. Most of what you are paying is capital. 

Also your interest rate is pretty low at the moment, less than 3%. When do you need to move to a new mortgage rate? Your interest rate will probably be higher than it is now when you do. 

If your mortgage interest rate is higher than the interest rate you are making on your Cash ISA then you should use your savings to clear off the mortgage now. Otherwise leave the cash where it is. 

Remember that you should have an emergency fund, don't put all your cash into the mortgage.