i assume 2007. Is it a student let? Its quite often to have them a fair way in advance, and if you leave it later you run the risk of not getting a place, or not getting the place you want. if you do decide to change your minds, you will be bound by the cntract, and the landlord could make you pay for however long that contract is for - perhaps a years rent. In practice, if they could get someone else before commencement you probably wouldnt have to pay but youd b taking a risk. If the 3 of you all sign seperatly, if 1 changes their mind they would be responsible for 1/3 of the rent presumaly, but in practice, would they pay it?