I have been very VERY fortunate to have been given a sum of money by a relative which we want to use as a deposit for our first house. We are thinking about putting it into those ISAs the government have set up where they add 25%. We have worked out if we get one each the money should be in in 19 months and ready for us to use with the top up. Is this a good idea? Or is there a catch? My dad always told me if something seems too good to be true it probably is.