If you are not a good saver and like to spend money, then again it could be sensible to use your deposit as soon as you have enough. This will eliminate nay temptation that you have to spend it on other things. It is also worth remembering that even if you do not pay off a big chunk of the house when you first buy it, if you have a flexible mortgage then you could be able to pay off a little extra each month and then still end up owing less and you may be able to pay it off early. This can be a great way to save money in the long term as if you pay off the mortgage early you will save a lot of money by no longer paying interest on the loan. These overpayments are optional and flexible which means that you only have to pay them when you can afford to and therefore if you do have extra expenses, you can stop doing it. However, as you have paid extra off the mortgage, you will still be saving money in interest. With some accounts you are able to draw overpayments back out as well, which means that if you do need money for something, then you can get hold of it. Obviously you will owe more and have to pay that interest, but you will have saved interest for some of the time and this will still help the overall cost of you loan to be lower.