A little piece of advice, look closely at your mortgage terms, if you are on a fixed % product for x number of years, there will be penalty fees to pay off the mortgage early. That could be £10,000+, you may also have to pay an early redemption fee of hundreds or thousands of pounds in addition.
My advice or what I would do is get all the information from the paperwork for debts, credit cards, mortgages, loans, HP. Sit down and go through them with a fine toothcomb. You may be better to over pay your mortgage for the next few months or years to the maximum amount without incurring additional fees, especially if you are on a say 2% interest only or repayment rate. Wait until you are clear of the fees, and then pay the mortgage off. Meanwhile look at sticking the money in as high as possible interest rate account. Look at the AER %, plus the term (years) of investment required.
So you may be better to put £150,000 (or whatever your outstanding balance of your mortgage is) into a 5% interest rate account for 1 year (or however long your fixed rate % on your mortgage product is) and earn £7500 in interest, rather than lose the penalty fees.
Pay off mortgage
£150,000
Early redemption fees for fixed rate product
£7,500
Total spend £157,500
Wait a year
Pay off Mortgage
£150,000
Early redemption fees
£0
Interest from high % account (5%)
£7,500
Total spend
£142,500
I hope that makes sense....