Hi there,
the one thing you didn't mention was if you were with or without a family. That question answered yes would hold a different answer as you have dependants. I wouldn't advise paying off that lump sum off your mortgage, what if you needed the money for something, once you put it into your mortgage you can't get it back. The fact that you can over pay your mortgage would be a better plan. Invest your money in a short term fixed deposit account or something similar. Depending on your age you could involve a little bit of a risk to try make you money but personally i like to play it safe so go with a capital secure fund. You can invest in some bonds which 25% of your investment is made available to you after a year and the 75%after 3, this would mean its not too long to wait. You could also go for a 7 or 30day notice account which offer you your funds back within these time frames. Always read the small print and go with a broker rather than a bank, the broker is independent. Hope this helps. Emma Gollogly.