I am asking this for someone else as although I have bought and sold a lot am not 100% sure on this and want an expert opinion!Ok my friends have just sold their main home and also have a flat as an investment.They got it with a buy to let mortgage 2 years ago even though they had no intention of letting it as they use it for work and weekends but this was the only way to fund a second home.They have never let it so no tenancy agrement etc but mortgage always paid and they can afford it I presume.They are now planning to buy a house a family hom and are doing the mortgage etc and I thought the loan on the flat would be taken into account when checking them out but they say no as the bank think its let it is totally seperate.is this right?You can be mortgaged to the eyeballs and its ok!